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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

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☒     ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2020

or

◻     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

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For the transition period from                      to

Commission file number: 001-34475

OMEROS CORPORATION

(Exact name of registrant as specified in its charter)

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(206) 676-5000

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

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Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.  Yes  ⌧   No   ◻

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Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.  Yes  ◻    No   ⌧

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Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.   Yes  ⌧    No  ◻

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Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).   Yes  ⌧    No  ◻

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Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ◻

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Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

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Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).   Yes  ☐    No  ⌧

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The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant as of the last business day of the registrant’s most recently completed second fiscal quarter was $762,308,158.

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As of February 25, 2021, the number of outstanding shares of the registrant’s common stock, par value $0.01 per share, was 61,933,806.

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DOCUMENTS INCORPORATED BY REFERENCE

Specified portions of the registrant’s proxy statement with respect to the 2021 Annual Meeting of Shareholders to be held June 4, 2021, which is to be filed pursuant to Regulation 14A within 120 days after the end of the registrant’s fiscal year ended December 31, 2020, are incorporated by reference into Part III of this Form 10-K.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934 (the “Exchange Act”), which are subject to the “safe harbor” created by those sections for such statements. Forward-looking statements are based on our management’s beliefs and assumptions and on currently available information. All statements other than statements of historical fact are “forward-looking statements.” Terms such as “anticipate,” “believe,” “could,” “estimate,” “expect,” “goal,” “intend,” “likely,” “may,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” and similar expressions and variations thereof are intended to identify forward-looking statements, but these terms are not the exclusive means of identifying such statements. Examples of these statements include, but are not limited to, statements regarding:

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Our actual results could differ materially from those anticipated in these forward-looking statements for many reasons, including the risks, uncertainties and other factors described in Item 1A of Part I of this Annual Report on Form 10-K under the heading “Risk Factors” and in Item 7 of Part II under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and in our other filings with the Securities and Exchange Commission (“SEC”). Given these risks, uncertainties and other factors, actual results or anticipated developments may not be realized or, even if substantially realized, they may not have the expected consequences to or effects on our company, business or operations. Accordingly, you should not place undue reliance on these forward-looking statements, which represent our estimates and assumptions only as of the date of the filing of this Annual Report on Form 10-K. You should read this Annual Report on Form 10-K completely and with the understanding that our actual results in subsequent periods may materially differ from current expectations. Except as required by applicable law, including the securities laws of the United States and the rules and regulations of the SEC, we assume no obligation to update or revise any forward-looking statements contained herein, whether as a result of any new information, future events or otherwise.

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OMEROS CORPORATION

ANNUAL REPORT ON FORM 10-K FOR THE YEAR ENDED DECEMBER 31, 2020

INDEX

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PART I

This Annual Report on Form 10-K contains forward-looking statements reflecting our current expectations that involve risks and uncertainties. Actual results may differ materially from those discussed in these forward-looking statements due to a number of factors, including those set forth in the section entitled “Risk Factors” and elsewhere in this Annual Report. Please refer to the special note regarding forward-looking statements at the beginning of this Annual Report on Form 10-K for further information.

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ITEM  1.             BUSINESS

Overview

We are a commercial-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, complement-mediated diseases, disorders of the central nervous system and immune-related diseases, including cancers.

Our drug product OMIDRIA® is marketed in the United States for use during cataract surgery or intraocular lens replacement for adult and pediatric patients. Our drug candidate narsoplimab is the subject of a biologics license application (“BLA”) under priority review by the U.S. Food and Drug Administration (“FDA”) for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (“HSCT-TMA”). We also have multiple Phase 3 and Phase 2 clinical-stage development programs in our pipeline, which are focused on: complement-mediated disorders, including immunoglobulin A (“IgA”) nephropathy, atypical hemolytic uremic syndrome (“aHUS”) and COVID-19. We have also initiated a Phase 1 clinical program for our MASP-3 inhibitor OMS906 targeting the alternative pathway of complement and have successfully completed a Phase 1 study in our phosphodiesterase 7 (“PDE7”) program focused on addiction. In addition, we have a diverse group of preclinical programs, including GPR174, a novel target in immuno-oncology that modulates a new cancer immunity axis that we discovered. Small-molecule and antibody inhibitors of GPR174 are part of our proprietary G protein-coupled receptor (“GPCR”) platform through which we control 54 GPCR drug targets and their corresponding compounds. We also possess a proprietary-asset-enabled antibody-generating technology. We have retained control of all commercial rights for OMIDRIA and each of our product candidates and programs.

Commercial Product -- OMIDRIA^® (phenylephrine and ketorolac intraocular solution) 1%/0.3%

Overview. OMIDRIA is approved by FDA for use during cataract surgery or intraocular lens (“IOL”) replacement to maintain pupil size by preventing intraoperative miosis (pupil constriction) and to reduce postoperative ocular pain. Outside the U.S., we have received approval from the European Commission (“EC”) to market OMIDRIA in the European Economic Area (“EEA”), for use during cataract surgery and other IOL replacement procedures for maintenance of intraoperative mydriasis (pupil dilation), prevention of intraoperative miosis and reduction of acute postoperative ocular pain.

OMIDRIA is a proprietary drug product containing two active pharmaceutical ingredients (“APIs”): ketorolac, an anti-inflammatory agent, and phenylephrine, a mydriatic, or pupil dilating, agent. Cataract and other lens replacement surgery involves replacement of the original lens of the eye with an artificial intraocular lens. OMIDRIA is added to standard irrigation solution used during cataract and lens replacement surgery and is delivered intracamerally, or within the anterior chamber of the eye, to the site of the surgical trauma throughout the procedure. Preventing pupil constriction is essential for these procedures and, if miosis occurs, the risk of damaging structures within the eye and other complications increases, as does the operating time required to perform the procedure.

United States. We launched OMIDRIA in the U.S. in the second quarter of 2015 and sell OMIDRIA primarily through wholesalers which, in turn, sell to ASCs and hospitals. CMS, the federal agency responsible for administering the Medicare program, granted transitional pass-through reimbursement status for OMIDRIA in 2014, effective from January 1, 2015 through December 31, 2017 and, in March 2018, Congress extended pass-through reimbursement status for a small number of drugs, including OMIDRIA, for an additional two years, running from October 1, 2018 through September 30, 2020. Pass-through status allows for separate payment (i.e., outside the packaged payment rate for the

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surgical procedure) under Medicare Part B. In CMS’ CY2021 Hospital Outpatient Prospective Payment System (HOPPS) and Ambulatory Surgical Center (ASC) Payment System Final Rule, CMS confirmed that OMIDRIA, as an otherwise policy packaged drug following OMIDRIA’s expiration of pass-through status on October 1, 2020, qualifies for separate payment when used on Medicare Part B patients in the ASC setting under CMS’ policy for non-opioid pain management surgical drugs. CMS made separate payment for OMIDRIA effective retroactively as of October 1, 2020. CMS’ current non-opioid separate payment policy and, as a result, separate payment for OMIDRIA thereunder, like other CMS policies in the OPPS and ASC systems, can be changed by CMS through its OPPS/ASC annual rulemaking and comment process. We believe that CMS will continue its separate payment policy for non-opioid pain management surgical drugs, which has been in effect since 2019, and that OMIDRIA will continue to be separately reimbursed when used in the ASC setting.

We have implemented a variety of programs and arrangements to facilitate the availability of OMIDRIA to cataract and IOL replacement patients in the U.S., including the following:

OMIDRIAssure provides coverage and reimbursement support services for surgeons and facilities to help remove uncertainties about coding, billing and coverage of OMIDRIA and to enable better access to the drug for patients facing financial barriers. Under our “Equal Access” patient assistance program, financially eligible uninsured and government-insured patients receive OMIDRIA free of charge for use during surgery. Through our “We Pay the Difference” program we pay the facility, on behalf of commercially insured patients, the difference between the facility’s acquisition cost for OMIDRIA, after accounting for any applicable volume discounts, and the amount covered by the patient’s insurance.

European Union and other International Territories. In July 2018, we placed OMIDRIA on the market in the European Union (“EU”) on a limited basis and continue to maintain the ongoing validity of the Marketing Authorization for OMIDRIA in EU member states and EEA countries. Decisions about price and reimbursement for OMIDRIA are made on a country-by-country basis and may be required before marketing may occur in a particular country. At this time we do not expect to see significant sales of OMIDRIA in any countries within the EEA or other international territories if we are unable to complete a broad sales launch in any such country either independently or through partnerships for the marketing and distribution of OMIDRIA.

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Our Product Candidates and Development Programs

Our clinical product candidates consist of the following:

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Our pipeline of development programs consists of the following:

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MASP Inhibitor Clinical Programs

MASP-2 Program - Narsoplimab (OMS721) - Lectin Pathway Disorders

Overview. Mannan-binding lectin-associated serine protease-2 (“MASP-2”), is a novel pro-inflammatory protein target involved in activation of the complement system, which is an important component of the immune system. The complement system plays a role in the body’s inflammatory response and becomes activated as a result of tissue damage or trauma or microbial pathogen invasion. Inappropriate or uncontrolled activation of the complement system can cause diseases characterized by serious tissue injury. Three main pathways can activate the complement system: classical, alternative and lectin. MASP-2 is recognized as the effector enzyme of the lectin pathway and is required for the function of this pathway. Importantly, inhibition of MASP-2 has been demonstrated not to interfere with the antibody-dependent classical complement activation pathway, a critical component of the acquired immune response to infection the abnormal function of which is associated with a wide range of autoimmune disorders.

Our proprietary, patented lead human monoclonal antibody targeting MASP-2, which we have referred to as OMS721, has been assigned the nonproprietary name narsoplimab. The current development focus for narsoplimab is diseases in which the lectin pathway has been shown to contribute to significant tissue injury and pathology. When not treated, these diseases are typically characterized by significant end organ injuries, such as kidney or central nervous system injury. We have completed our pivotal clinical trial for narsoplimab in HSCT-TMA, and Phase 3 clinical programs are in process for narsoplimab in IgA nephropathy and aHUS. Narsoplimab is also being evaluated for treatment of COVID-19 in an adaptive platform trial and has been used under compassionate use to treat COVID-19 patients in Italy and in the U.S.

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Thrombotic Microangiopathies

HSCT-TMA. In November 2020, we completed the rolling submission to FDA of our BLA for narsoplimab for the treatment of HSCT-TMA, a frequently lethal complication of HSCT. The BLA has been accepted for filing by FDA and granted priority review with an FDA action date under the Prescription Drug User Fee Act (“PDUFA”) of July 17, 2021.

In October 2020, we reported final clinical data from our pivotal trial of narsoplimab in HSCT-TMA. The single-arm, open-label trial included safety and efficacy endpoints that were previously agreed to with FDA. These endpoints were assessed for (1) all 28 patients who received at least one dose of narsoplimab and (2) patients who received the protocol-specified dosing of at least four weeks of narsoplimab.

The primary efficacy endpoint in the trial was the proportion of patients who achieved designated “responder” status based on improvement in HSCT-TMA laboratory markers and clinical status. This is referred to as the “complete response rate.” The primary laboratory markers that were evaluated were platelet count and lactate dehydrogenase (“LDH”), levels, while improvement in clinical status was evaluated based on organ function and transfusions. Each patient was required to show improvement in both laboratory markers and clinical status to be considered a responder. All others were considered non-responders.

Among patients who received at least one dose of narsoplimab, the complete response rate was 61% (95% confidence interval [CI] 40.6 to 78.5; p<0.0001), while the complete response rate among patients who received the protocol-specified narsoplimab treatment of at least four weeks of dosing was 74% (95% CI 51.6 to 89.8; p<0.0001). The response rates and their respective lower levels of the 95% confidence intervals are a multiple of the pre-specified efficacy threshold of 15%.

Secondary endpoints in the trial were survival rates and change from baseline in HSCT-TMA laboratory markers. Among all treated patients, 68% survived for at least 100 days following HSCT-TMA diagnosis, while 83% of patients who received treatment for at least four weeks and 94% of the responders achieved this endpoint. Median overall survival was 274 days among all patients and 361 days among patients who received the protocol-specified treatment of at least four weeks. Median survival could not be estimated for responders because more than half of the responders were alive at last follow-up. Results also included statistically significant improvements in platelet count, LDH and haptoglobin. The treated population had multiple high-risk features that portend a poor outcome, including the persistence of HSCT-TMA despite modification of immunosuppression (which was a criterion for entry into the trial), graft-versus-host disease, significant infections, non-infectious pulmonary complications and neurological findings. The most common adverse events observed in the trial were nausea, vomiting, diarrhea, hypokalemia, neutropenia and fever, which are all common in stem-cell transplant patients. Six deaths occurred during the trial. These were due to sepsis, progression of the underlying disease, and graft-versus-host disease with TMA. All of these are common causes of death in this patient population.

In Europe, the EMA has confirmed narsoplimab’s eligibility for EMA’s centralized review of a single MAA that, if approved, authorizes the product to be marketed in all EU member states and EEA countries. We are targeting to complete our MAA submission in 2021.

In the U.S., FDA has granted narsoplimab (1) breakthrough therapy designation in patients who have persistent TMA despite modification of immunosuppressive therapy, (2) priority review for the HSCT-TMA BLA, (3) orphan drug designation for the prevention (inhibition) of complement-mediated TMAs, and (4) orphan drug designation for the treatment of HSCT-TMA. The EC also granted narsoplimab designation as an orphan medicinal product for treatment in hematopoietic stem cell transplantation.

aHUS. We have an ongoing Phase 3 clinical program in patients with aHUS with active sites in the U.S., Europe and Asia. The single-arm, open-label Phase 3 clinical trial in patients with newly diagnosed or ongoing aHUS is enrolling. This trial is targeting approximately 40 patients for EU approval and U.S. accelerated approval with 80 patients required for full approval in the U.S. The trial includes multiple sites in the U.S., Asia and Europe, and is actively enrolling, though enrollment has been slowed in part due to prioritizing the use of resources within our narsoplimab programs on HSCT-TMA, IgA nephropathy, and COVID-19. Dosing consists of an initial IV loading

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followed by daily subcutaneous dosing. Based on discussions with FDA and the EMA, we expect that the clinical package for the BLA would be similar to that which formed the basis of approval for Soliris^® (eculizumab), which is marketed by Alexion Pharmaceuticals, Inc.

The FDA has granted to narsoplimab orphan drug designation for the prevention (inhibition) of complement-mediated TMAs and fast-track designation for the treatment of patients with aHUS.

Renal Disease

Phase 3 Program - IgA Nephropathy. Patient enrollment is ongoing in our Phase 3 clinical trial evaluating narsoplimab in IgA nephropathy, which is referred to as ARTEMIS-IGAN. The single Phase 3 trial design is a randomized, double-blind, placebo-controlled multicenter trial in patients at least 18 years of age with biopsy-confirmed IgA nephropathy and with 24-hour urine protein excretion greater than 1 g/day at baseline on optimized renin-angiotensin system blockade. This trial includes a run-in period. Initially, patients are expected to receive an IV dose of study drug each week for 12 weeks; additional weekly dosing can be administered to achieve optimal response. The primary endpoint, which could suffice for full or accelerated approval depending on the effect size, is reduction in proteinuria at 36 weeks after the start of dosing. The trial is designed to allow intra-trial adjustment in sample size. For the purposes of safety and efficacy assessments, the initial sample size for the proteinuria endpoint is estimated at 140 patients in each of the treatment and placebo groups. This will include a subset of patients with high levels of proteinuria (i.e., equal to or greater than 2 g/day) at baseline, and a substantial improvement at 36 weeks in this subset of patients alone could potentially form the basis for approval. We believe that the trial design will allow assessment for either full or accelerated approval at 36 weeks based on proteinuria results either (1) across the general population of study patients or (2) in the high-proteinuria subset of patients. In the event of full approval, estimated glomerular filtration rate (“eGFR”) becomes a safety endpoint only. In the event that the primary endpoint at 36 weeks results in accelerated approval from FDA, change in eGFR is expected to be assessed at approximately two years after the start of dosing. These eGFR data, if satisfactory, would then likely form the basis for full approval. In response to investigators’ concerns about extended withholding of narsoplimab treatment from any high-proteinuria patient initially randomized to the placebo-treated group, FDA will allow patients in that sub-population open-label treatment with narsoplimab after at least 1 year of blinded treatment.

In the U.S., narsoplimab has received breakthrough therapy and orphan drug designations from FDA for the treatment of IgA nephropathy. In Europe, narsoplimab has received orphan drug designation from the EMA in patients with IgA nephropathy.

Phase 2 Clinical Trial - Renal Diseases. We have been conducting a Phase 2 clinical trial in patients with complement-associated renal diseases, specifically designed to cover: (1) IgA nephropathy; (2) membranous nephropathy; and (3) lupus nephritis. An initial open-label cohort of patients completed treatment in May 2017. In August 2020, a manuscript detailing the results of the Phase 2 clinical trial in patients with IgA nephropathy was published in the peer-reviewed journal Kidney International Reports.

COVID-19. In March 2020, in response to a request from physicians at the Papa Giovanni XXIII Hospital in Bergamo, Italy, we initiated a compassionate use program for narsoplimab to treat patients with severe COVID-19 requiring mechanical ventilation.

The initial cohort treated under this compassionate use program included a total of six COVID-19 patients treated with narsoplimab under compassionate use, all with acute respiratory distress syndrome (“ARDS”) and requiring continuous positive airway pressure (“CPAP”) or intubation. At baseline, circulating endothelial cell (“CEC”) counts and serum levels of interleukin-6 (“IL-6”), interleukin-8 (“IL-8”), C-reactive protein (“CRP”), LDH, D-dimer and aspartate aminotransferase (“AST”) were markedly elevated. During the course of the compassionate use program, institutional guidelines at the treating hospital were updated to require that all COVID-19 patients in the hospital receive steroids. One patient treated with narsoplimab did not receive steroids. Of the five narsoplimab-treated patients who received steroids, two initiated them after already improving such that CPAP was no longer required or was discontinued the following day. The study evaluated CEC counts in a separate group of four patients receiving only steroids for a short duration, and the counts were found to be unaffected by steroid administration. This suggests that any beneficial

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effect of steroids on COVID-19-associated endothelial damage may be delayed and had little effect on the recovery course of the narsoplimab-treated patients who initiated steroid treatment after improving.

Narsoplimab treatment was associated with rapid and sustained reduction across all of these markers of endothelial damage and inflammation. In addition, massive bilateral pulmonary thromboses, seen in two of the patients, resolved while on narsoplimab. All six narsoplimab-treated patients recovered, survived and were discharged. Narsoplimab was well tolerated and no adverse drug reactions were reported. Two control groups with similar baseline characteristics were used for retrospective comparison, both showing substantial mortality rates of 32% and 53%. A manuscript detailing the results of the initial cohort of Bergamo patients treated with narsoplimab was published in the peer-reviewed journal Immunobiology.

All six patients were evaluated five to six months after cessation of narsoplimab treatment. None of them showed any clinical or laboratory evidence of long-term effects of COVID-19, such as cognitive impairment or cardiac, pulmonary or other organ disorder, commonly seen following resolution of initial COVID-19 symptoms.

Endothelial damage and resultant thromboses are significant to the pathophysiology of COVID-19, and we believe these data illustrate the importance of inhibiting the lectin pathway to treat critically ill COVID-19 patients. Endothelial damage activates the lectin pathway of complement. We believe the results observed following narsoplimab treatment in critically ill COVID-19 patients at Papa Giovanni were consistent with those seen in HSCT-TMA and underscore the pathophysiologic similarities between these two disorders. Narsoplimab has been shown to inhibit lectin pathway activation and to block the MASP-2-mediated conversion of prothrombin to thrombin, microvascular injury-associated thrombus formation and the activation of factor XII as well as the MASP-2-mediated activation of kallikrein. We believe that the anticoagulant effects of narsoplimab may provide therapeutic benefits in both HSCT-TMA and COVID-19.

Following treatment of the initial six patients under the compassionate use program in Italy, we have continued compassionate-use treatment with nine more patients in Italy and four patients in the U.S. All of these patients prior to receiving narsoplimab were severely ill, intubated, had multiple comorbidities, and had failed other therapies, including anti-virals, targeted anti-inflammatory therapeutics, convalescent plasma and steroids. Following treatment with narsoplimab, the laboratory improvements and clinical outcomes of these patients are similar to those seen in the initial cohort of Bergamo patients.

Narsoplimab is also the only complement inhibitor included in the I-SPY COVID-19 platform trial sponsored by Quantum Leap Healthcare Collaborative, which is evaluating drugs and investigational products for the treatment of critically ill COVID-19 patients. The trial utilizes Quantum Leap Healthcare Collaborative's adaptive platform trial design, which is intended to increase trial efficiency by minimizing the number of participants and time required to evaluate potential treatments.

Discussions regarding the use of narsoplimab in COVID-19 with leaders across various U.S. government agencies as well as international regulatory authorities and global healthcare organizations continue to progress.

Licensing Arrangements. We hold worldwide exclusive licenses to rights related to MASP-2, the antibodies targeting MASP-2 and the therapeutic applications for those antibodies from the University of Leicester, from its collaborator, the Medical Research Council at Oxford University (“MRC”), and from Helion Biotech ApS (“Helion”). For a more detailed description of these licenses, see “License and Development Agreements” below.

MASP-3 Program - OMS906 - Alternative Pathway Disorders

Overview. As part of our MASP program, we have identified mannan-binding lectin-associated serine protease 3 (“MASP-3”), which has been shown to be the key activator of the complement system’s alternative pathway (“APC”), and we believe that we are the first to make this and related discoveries associated with the APC. The complement system is part of the immune system’s innate response, and the APC is considered the amplification loop within the complement system. MASP-3 is responsible for the conversion of pro-factor D to factor D; converted factor D is necessary for the activation of the APC. Based on our alternative pathway-related discoveries, we have expanded our intellectual property position to protect our inventions stemming from these discoveries beyond MASP-2 associated

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inhibition of the lectin pathway to include inhibition of the alternative pathway. Our current primary focus in this program is developing MASP-3 inhibitors for the treatment of disorders related to the APC. We believe that MASP-3 inhibitors have the potential to treat patients suffering from a wide range of diseases and conditions, including: paroxysmal nocturnal hemoglobinuria (“PNH”); multiple sclerosis; neuromyelitis optica; age-related macular degeneration; Alzheimer’s disease; systemic lupus erythematosus; diabetic retinopathy; chronic obstructive pulmonary disease; antineutrophil cytoplasmic antibody-associated vasculitis; anti-phospholipid syndrome; atherosclerosis; myasthenia gravis and others. Our OMS906 monoclonal antibody program has generated positive data in a well-established animal model associated with PNH as well as strong pharmacodynamic activity in non-human primates. The program has also generated positive data in a well-established animal model of arthritis.

In September 2020 we began enrollment and dosing in a placebo-controlled, double-blind, single-ascending-dose and multiple-ascending-dose Phase 1 clinical trial to evaluate the safety, tolerability, pharmacodynamics and pharmacokinetics of OMS906. We have completed all of the intravenous dosing cohorts in the single-ascending-dose study and expect to begin subcutaneous dosing in March 2021. Initial data from the Phase 1 trial are expected in the second quarter of 2021.

Licensing Arrangements. We jointly own and hold worldwide exclusive license rights related to therapeutic applications for inhibiting MASP-3 from the University of Leicester. For a more detailed description of these licenses, see “License and Development Agreements” below.

MASP Inhibitor Preclinical Programs

Other MASP Inhibitor Preclinical Programs

We have generated positive preclinical data from MASP-2 inhibition in in vivo models of AMD, myocardial infarction, diabetic neuropathy, stroke, ischemia-reperfusion injury, and other diseases and disorders.

We are also developing a longer-acting second generation antibody targeting MASP-2, which we are targeting for initiation of clinical trials in early 2022. Development efforts are also directed to a small-molecule inhibitor of MASP-2 designed for oral administration, as well as small-molecule inhibitors of MASP-3 and bispecific small- and large-molecule inhibitors of MASP-2/-3.

Other Clinical Programs

PDE7 Program - OMS527

Overview. Our PDE7 program is based on our discoveries of previously unknown links between PDE7 and any addiction or compulsive disorder, and between PDE7 and any movement disorders, such as Parkinson’s disease. PDE7 appears to modulate the dopaminergic system, which plays a significant role in regulating both addiction and movement. We believe that PDE7 inhibitors could be effective therapeutics for the treatment of addictions and compulsions as well as for movement disorders. Data generated in preclinical studies support the use of PDE7 inhibitors in both of these therapeutic areas.

In September 2019, we reported positive results from our completed Phase 1 clinical trial designed to assess the safety, tolerability and pharmacokinetics of the compound in healthy subjects. In the double blind, randomized Phase 1 study, the study drug, referred to as OMS182399, met the primary endpoints of safety and tolerability and showed a favorable and dose-proportional pharmacokinetic profile supporting once-daily dosing. There was no apparent food effect on plasma exposure to OMS182399. Continued clinical development in our PDE7 program is subject to allocation of financial and other resources, which are currently prioritized for other programs.

Exclusive License Agreement with Daiichi Sankyo Co., Ltd. We hold an exclusive license to certain PDE7 inhibitors claimed in patents and pending patent applications owned by Daiichi Sankyo Co., Ltd. (“Daiichi Sankyo”), as successor-in-interest to Asubio Pharma Co., Ltd., or, for use in the treatment of movement, addiction and compulsive disorders as

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well as other specified indications. For a more detailed description of our agreement with Daiichi Sankyo, see “License and Development Agreements” below.

PPARγ Program - OMS405

Overview. In our peroxisome proliferator-activated receptor gamma (“PPARγ”) program, we have engaged in development of proprietary compositions that include PPARγ agonists for the treatment and prevention of addiction to substances of abuse, which may include opioids, nicotine and alcohol. We believe that Omeros is the first to demonstrate a link between PPARγ and addiction disorders. Data from clinical studies and from animal models of addiction suggest that PPARγ agonists could be efficacious in the treatment of a wide range of addictions.

Clinical trials. Our collaborators at The New York State Psychiatric Institute have completed two Phase 2 clinical trials related to our PPARγ program. These studies evaluated a PPARγ agonist, alone or in combination with other agents, for treatment of addiction to heroin and to nicotine. The published results of the heroin study demonstrated that, although not altering the reinforcing or positive subjective effects of heroin, the PPARγ agonist significantly reduced heroin craving and overall anxiety. The National Institute on Drug Abuse provided substantially all of the funding for these clinical trials and solely oversaw the conduct of these trials. We have the right or expect to be able to reference the data obtained from these studies for subsequent submissions to FDA and continue to retain all other rights in connection with the PPARγ program. We have also reported positive results (i.e., decreased cravings and protection of brain white matter) from a Phase 2 clinical trial conducted by an independent investigator evaluating the effects of a PPARγ agonist in patients with cocaine use disorder.

An investigator-sponsored study on the prevention of relapse following treatment of cocaine use disorder is expected to begin enrolling in March 2021. The study is funded by the National Institute on Drug Abuse (“NIDA”).

Patent Assignment Agreement with Roberto Ciccocioppo, Ph.D. We acquired the patent applications and related intellectual property rights for our PPARγ program in February 2009 from Roberto Ciccocioppo, Ph.D., of the Università di Camerino, Italy, pursuant to a patent assignment agreement. For a more detailed description of our agreement with Dr. Ciccocioppo, see “License and Development Agreements” below.

Preclinical Programs and Platforms

GPCR Platform

Overview. GPCRs, which are cell surface membrane proteins involved in mediating both sensory and nonsensory functions, comprise one of the largest families of proteins in the genomes of multicellular organisms. Sensory GPCRs are involved in the perception of light, odors, taste and sexual attractants. Non-sensory GPCRs are involved in metabolism, behavior, reproduction, development, hormonal homeostasis and regulation of the central nervous system. The vast majority of GPCR drug targets are non-sensory. Although GPCRs form a super-family of receptors, individual GPCRs display a high degree of specificity and affinity for the functionally active molecules, or ligands, that bind to a given receptor. Ligands can either activate the receptor (agonists) or inhibit it (antagonists and inverse agonists). When activated by its ligand, the GPCR interacts with intracellular G proteins, resulting in a cascade of signaling events inside the cell that ultimately leads to the particular function linked to the receptor. Without a known ligand, there is no template from which medicinal chemistry efforts can be readily initiated, nor a means to identify the GPCR’s signaling pathway and, therefore, drugs are very difficult to develop against orphan GPCRs. “Unlocking” these orphan GPCRs by identifying one or more of their respective ligands could lead to the development of drugs that act at these new targets.

To our knowledge, Omeros’ technology is the first commercially viable technology capable of identifying ligands of orphan GPCRs in high throughput. We have developed a proprietary cellular redistribution assay (“CRA”), which we use in a high-throughput manner to identify synthetic ligands, including antagonists, agonists and inverse agonists, that bind to and affect the function of orphan GPCRs. We have screened Class A orphan GPCRs against our small-molecule chemical libraries using the CRA. As of December 31, 2020, we had identified and confirmed compounds that interact with 54 of the 81 Class A orphan GPCRs linked to a wide range of indications including cancer as well as metabolic, cardiovascular, immunologic, inflammatory and central nervous system disorders.

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One of our priorities in this program is GPR174, which is involved in the modulation of the immune system. In ex vivo human studies, our small-molecule inhibitors targeting GPR174 upregulate the production of cytokines, block multiple checkpoints and tumor promoters, and suppress regulatory T-cells. Based on our data, we believe that GPR174 controls a major pathway in cancer and modulation of the receptor could provide a seminal advance in immuno-oncologic treatments for a wide range of tumors. Our recent discoveries suggest a new approach to cancer immunotherapy that targets inhibition of GPR174 and can be combined with and significantly improve the tumor-killing effects of adenosine pathway inhibitors. These discoveries include (1) identification of cancer-immunity pathways controlled by GPR174, (2) the identification of phosphatidylserine as a natural ligand for GPR174, (3) a collection of novel small-molecule inhibitors of GPR174 and (4) a synergistic enhancement of “tumor-fighting” cytokine production by T cells following the combined inhibition of both GPR174 and the adenosine pathway, another key metabolic pathway that regulates tumor immunity. In November 2019, we announced that our studies in mouse models of melanoma and colon carcinoma found that GPR174-deficiency resulted in significantly reduced tumor growth and improved survival of the animals versus normal mice. We are developing both small-molecule and antibody inhibitors of GPR174 with the objective of moving compounds into human trials and exploring several of our other GPCR targets as well.

We have also conducted in vitro and in vivo preclinical efficacy studies and engaged in compound optimization for a number of targets including GPR151, which is linked to schizophrenia, cognition and obesity, and GPR161, which is associated with triple negative breast cancer and various sarcomas.

In addition to Class A orphan GPCRs, we have screened orphan and non-orphan Class B receptors. Class B GPCRs have large extracellular domains and their natural ligands are generally large peptides, making the development of orally active, small-molecule drugs against these receptors, such as glucagon and parathyroid hormone, a persistent challenge. Our CRA technology finds functionally active small molecules for GPCRs, which we believe could lead to the development of oral medications for many of the Class B GPCRs. While our focus to date has remained on Class A orphan GPCRs, we have identified and confirmed sets of compounds that interact selectively with, and modulate signaling of, a small subset of Class B GPCRs, namely glucagon-like peptide-1 receptor and parathyroid hormone 1 receptor.

GPCR Platform Funding Agreements with Vulcan Inc. and the Life Sciences Discovery Fund. In October 2010, we entered into funding agreements for our GPCR program with Vulcan Inc. and its affiliate, which we refer to collectively as Vulcan, and with the Life Sciences Discovery Fund Authority (“LSDF”), a granting agency of the State of Washington. For a more detailed description of these agreements, see “License and Development Agreements” below.

Sales and Marketing

We have retained all worldwide marketing and distribution rights to OMIDRIA, our product candidates and our development programs. This allows us to market and sell OMIDRIA and any product candidates that is approved in the future, either independently, through arrangements with third parties, or via some combination of these approaches.

With respect to OMIDRIA in the U.S., we have developed our own internal marketing and sales capabilities and, as of December 31, 2020, we employed 63 sales and reimbursement team members. In July 2018 we placed OMIDRIA on the market in the EU on a limited basis, which maintained the ongoing validity of the European marketing authorization for OMIDRIA for a period of three years and we expect to continue to market the product within Europe on a limited basis for purposes of maintaining the marketing authorization. At this time we do not expect to generate, in the near-term, significant sales of OMIDRIA outside of the U.S.

Manufacturing, Supply and Commercial Operations

OMIDRIA. We use third parties to produce, store and distribute OMIDRIA and currently do not own or operate manufacturing facilities. Our agreements with these third parties include confidentiality and intellectual property provisions to protect our proprietary rights related to OMIDRIA. We require manufacturers that produce APIs and finished drug products to operate in accordance with current Good Manufacturing Practices (“cGMPs”) and all other applicable laws and regulations.

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We have an agreement with Hospira Worldwide, Inc. (“Hospira”), a wholly owned subsidiary of Pfizer, Inc., to provide commercial supply of OMIDRIA. Under the agreement with Hospira (the “Hospira OMIDRIA Agreement”), Hospira has agreed to manufacture and supply, and we have agreed to purchase, a minimum percentage of our requirements of OMIDRIA for commercial sales and clinical supplies for the development of additional therapeutic indications in the U.S. In addition, Hospira has agreed to manufacture and supply a portion of our requirements of OMIDRIA in the EU, with there being no minimum purchase and supply requirement in the EU if the parties do not enter into such an amendment to the agreement. We have not yet entered into such an agreement with Hospira relating to the supply of OMIDRIA for the EU. The Hospira OMIDRIA Agreement expires in February 2022, but may be terminated prior to the end of its term upon the occurrence of certain specified events, including without limitation an uncured breach of the agreement or bankruptcy or dissolution of a party. Upon termination of the Hospira OMIDRIA Agreement, except in the case of termination for an uncured breach by Hospira, we will be required to purchase all of Hospira’s inventory of OMIDRIA and, if applicable, all work-in-progress inventory and to reimburse Hospira for all supplies purchased or ordered based on firm purchase orders or our estimates of its requirements of OMIDRIA.

We have used multiple suppliers for the APIs for OMIDRIA in the past and we intend to leverage Hospira’s sourcing of APIs in the future under the Hospira OMIDRIA Agreement. Given the large amount of these APIs manufactured annually by these and other suppliers, and the quantities of these APIs that we have on hand, we anticipate that we will be capable of addressing our commercial API supply needs for OMIDRIA in the near-term. We have not yet signed commercial agreements with suppliers for the supply of all of our anticipated commercial quantities of these APIs for OMIDRIA, although we may elect to do so in the future. In addition to our supply agreement with Hospira, we have executed an agreement with a second manufacturing partner for supply of OMIDRIA. Work to bring the second manufacturer online is ongoing and we anticipate OMIDRIA to be available from this manufacturer beginning in 2021.

In the U.S., we sell OMIDRIA through a limited number of wholesalers that distribute the product to ASCs and hospitals. Title transfers upon delivery of OMIDRIA to the wholesaler. We use a single third-party logistics provider to handle warehousing and final packaging of our commercial supply of OMIDRIA in the U.S. and to ship OMIDRIA to our wholesalers. Our third-party logistics provider also performs certain support services on our behalf. Virtually all of our revenues for the last three fiscal years were generated from OMIDRIA product sales in the U.S. Our four major distributors--AmerisourceBergen Corporation, Cardinal Health, Inc., McKesson Corporation and FFF Enterprises, Inc.--together with entities under their common control each accounted for 10% or more, and nearly 100% in aggregate, of our total revenue in 2020. For additional information regarding our major customers, see Part II, Item 8, “Note 2—Significant Accounting Policies” to our Consolidated Financial Statements in this Annual Report on Form 10 K

Product Candidates. We have laboratories in-house for analytical method development, bioanalytical testing, formulation, stability testing and small-scale compounding of laboratory supplies of product candidates. We utilize contract manufacturers to produce sufficient quantities of product candidates for use in preclinical and clinical studies and to store and distribute our product candidates. We require manufacturers that produce APIs and finished drug products for clinical use to operate in accordance with cGMPs and all other applicable laws and regulations. We anticipate that we will rely on contract manufacturers to develop and manufacture our product candidates for commercial sale. We maintain agreements with potential and existing manufacturers that include confidentiality and intellectual property provisions to protect our proprietary rights related to our product candidates.

In July 2019, we entered into a master services agreement with Lonza Biologics Tuas Pte. Ltd. (“Lonza”) for the commercial production of narsoplimab and for certain regulatory support and related services to be provided by Lonza from time to time. Under the agreement Lonza will manufacture narsoplimab pursuant to purchase orders issued in accordance with forecasts that we provide. We will purchase narsoplimab that meets agreed specifications in batches, with the price per batch varying according to the total number of batches ordered for serial production in a single manufacturing campaign. We are obligated to purchase a minimum number of batches annually beginning on a specified anniversary of the first commercial sale of narsoplimab in either the U.S. or EU. We may be obligated to pay certain fees to Lonza upon cancellation of purchase orders.

The initial term of the agreement expires five years after the first commercial sale of narsoplimab in either the U.S. or EU and is subject to automatic renewal for an additional four-year term unless we provide notice of non-renewal at least three years prior to the end of the initial term. In addition, either party may terminate the agreement, subject to

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applicable notice and cure periods under certain circumstances. Other than our agreement for commercial supply of narsoplimab, we have not yet entered into a commercial supply agreement for any of our product candidates.

License and Development Agreements

MASP Program. Under our exclusive license agreements with the University of Leicester and MRC, we have agreed to pay royalties to each of the University of Leicester and MRC that are a percentage of any proceeds we receive from the licensed MASP-2 technology during the terms of the agreements. Our exclusive license agreement with the University of Leicester, but not our agreement with the MRC, also applies to other MASPs. The continued maintenance of these agreements requires us to undertake development activities. We must pay low single-digit percentage royalties with respect to proceeds that we receive from products incorporating certain intellectual property within the licensed technology that are used, manufactured, directly sold or directly distributed by us, and we must pay royalties, in the range of a low single-digit percentage to a low double-digit percentage, with respect to proceeds we receive from sublicense royalties or fees that we receive from third parties to which we grant sublicenses to certain intellectual property within the licensed technology. We did not make any upfront payments for these exclusive licenses nor are there any milestone payments or reversion rights associated with these license agreements. We retain worldwide exclusive licenses from these institutions to develop and commercialize any intellectual property rights developed in the sponsored research. The term of each license agreement ends when there are no longer any pending patent applications, applications in preparation or unexpired issued patents related to any of the intellectual property rights we are licensing under the agreement. Both of these license agreements may be terminated prior to the end of their terms by us for convenience or by one party if the other party (1) breaches any material obligation under the agreement and does not cure such breach after notice and an opportunity to cure or (2) is declared or adjudged to be insolvent, bankrupt or in receivership and materially limited from performing its obligations under the agreement.

In April 2010, we entered into an exclusive license agreement with Helion, pursuant to which we received a royalty-bearing, worldwide exclusive license to all of Helion’s intellectual property rights related to MASP-2 antibodies, polypeptides and methods in the field of inhibition of mannan-binding lectin-mediated activation of the complement system for the prevention, treatment or diagnosis of any disease or condition. We are obligated to make remaining development and sales milestone payments to Helion of up to approximately $5.4 million upon the achievement of certain events, such as receipt of marketing approval, and reaching specified sales milestones. We are obligated to pay Helion a low single-digit percentage royalty on net sales of a MASP-2 inhibitor product covered by the patents licensed under the agreement. The term of the agreement continues so long as there is a valid, subsisting and enforceable claim in any patents or patent applications covered by the agreement. The agreement may be terminated sooner by either party following a material breach of the agreement by the other party that has not been cured within 90 days.

PPARγ. We acquired the patent applications and related intellectual property rights for our PPARγ program in February 2009 from Roberto Ciccocioppo, Ph.D. of the Università di Camerino, Italy, pursuant to a patent assignment agreement. In February 2011, we amended the agreement to include all intellectual property rights, including patent applications, related to nutraceuticals that increase PPARγ activity. Under the amended agreement, we have agreed to pay Dr. Ciccocioppo a low-single digit percentage royalty on net sales of any products that are covered by any patents that issue from the patent applications that we acquired from him. In addition, if we grant any third parties rights to manufacture, sell or distribute any such products, we must pay to Dr. Ciccocioppo a percentage of any associated fees we receive from such third parties in the range of low single-digits to low double-digits depending on the stage of development at which such rights are granted. We have also agreed to make total milestone payments of up to $3.8 million to Dr. Ciccocioppo upon the occurrence of certain development events, such as patient enrollment in a Phase 1 clinical trial and receipt of marketing approval of a product candidate covered by any patents that issue from the patent applications that we acquired from him. If we notify Dr. Ciccocioppo that we have abandoned all research and development and commercialization efforts related to the patent applications and intellectual property rights we acquired from him, Dr. Ciccocioppo has the right to repurchase those assets from us at a price equal to a double-digit percentage of our direct and indirect financial investments and expenditures in such assets. If he does not exercise his right to repurchase those assets within a limited period of time by paying the purchase price, we will have no further obligations to sell those assets to Dr. Ciccocioppo. The term of our agreement with Dr. Ciccocioppo ends when there are no longer any valid and enforceable patents related to the intellectual property rights we acquired from him, provided that either party may terminate the agreement earlier in case of an uncured breach by the other party. Under the terms of the

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agreement, we have agreed to pay a portion of the payments due to Dr. Ciccocioppo to the Università di Camerino without any increase to our payment obligations.

PDE7. Under an agreement with Daiichi Sankyo, we hold an exclusive worldwide license to PDE7 inhibitors claimed in certain patents and pending patent applications owned by Daiichi Sankyo for use in the treatment of (1) movement disorders and other specified indications, (2) addiction and compulsive disorders and (3) all other diseases except those related to dermatologic conditions. Under the agreement, we agreed to make milestone payments to Daiichi Sankyo of up to an aggregate total of $33.5 million upon the achievement of certain events in each of these three fields; however, if only one of the three indications is advanced through the milestones, the total milestone payments would be $23.5 million. The milestone payment events include successful completion of preclinical toxicology studies; dosing of human subjects in Phase 1, 2 and 3 clinical trials; receipt of marketing approval of a PDE7 inhibitor product candidate; and reaching specified sales milestones. In addition, Daiichi Sankyo is entitled to receive from us a low single-digit percentage royalty of any net sales of a PDE7 inhibitor licensed under the agreement by us and/or our sublicensee(s) provided that, if the sales are made by a sublicensee, then the amount payable by us to Daiichi Sankyo is capped at an amount equal to a low double-digit percentage of all royalty and specified milestone payments received by us from the sublicensee.

The term of the agreement with Daiichi Sankyo continues so long as there is a valid, subsisting and enforceable claim in any patents covered by the agreement. The agreement may be terminated sooner by us, with or without cause, upon 90 days advance written notice or by either party following a material breach of the agreement by the other party that has not been cured within 90 days or immediately if the other party is insolvent or bankrupt. Daiichi Sankyo also has the right to terminate the agreement if we and our sublicensee(s) cease to conduct all research, development and/or commercialization activities for a PDE7 inhibitor covered by the agreement for a period of six consecutive months, in which case all rights held by us under Daiichi Sankyo’s patents will revert to Daiichi Sankyo.

GPCR Platform Funding Agreements with Vulcan Inc. and the Life Sciences Discovery Fund. In October 2010, we entered into funding agreements for our GPCR program with Vulcan and LSDF. We received $20.0 million and $5.0 million, respectively, under the agreements with Vulcan and LSDF. Under these agreements, we have agreed to pay Vulcan and LSDF tiered percentages of the net proceeds, if any, that we derive from the GPCR program. The percentage rates of net proceeds payable to Vulcan and LSDF decrease as the cumulative net proceeds reach specified thresholds, and the blended percentage rate payable to Vulcan and LSDF in the aggregate is in the mid-teens with respect to the first approximately $1.5 billion of cumulative net proceeds that we receive from our GPCR program. If we receive cumulative net proceeds in excess of approximately $1.5 billion, the percentage rate payable to Vulcan and LSDF in the aggregate decreases to one percent. An acquirer of the assets in our GPCR program may be required, and an acquirer of our company would be required, to assume all of our payment and other obligations under our agreements with Vulcan and LSDF.

Under our agreement with Vulcan, we granted Vulcan a security interest in our personal property related to the GPCR program, other than intellectual property, which security interest is junior to any existing or future security interests granted in connection with a financing transaction and which will be released automatically after Vulcan receives $25.0 million under the agreement. We also agreed not to grant any liens on intellectual property related to the GPCR program without Vulcan’s consent, subject to specified exceptions. These restrictions could limit our ability to pursue business opportunities involving the GPCR program or reduce the price that a potential buyer would pay for the GPCR assets. If we default under our agreement with Vulcan, in certain circumstances Vulcan may, subject to the rights of any holders of senior security interests, take control of such pledged assets. If we are liquidated, Vulcan’s right to receive any payments then due under our agreement would be senior to the rights of the holders of our common stock to receive any proceeds from the liquidation of our GPCR program assets.

The term of our agreement with Vulcan is 35 years, provided that the term will automatically extend until the cumulative net proceeds that we receive from the GPCR program are approximately $1.5 billion. The term of our agreement with LSDF expires on the six-month anniversary following the last date that we deliver a report related to our incurrence of grant-funded expenses described in the agreement, provided that certain obligations will survive the expiration of the term. The term of our payment obligations to LSDF is the same as that under our agreement with Vulcan.

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OMIDRIA. We entered into settlement agreements and consent judgments with (1) Par Pharmaceutical, Inc. and its subsidiary, Par Sterile Products, LLC (collectively, “Par”) and (2) Lupin Ltd. and Lupin Pharmaceuticals, Inc. (collectively, “Lupin”) in October 2017 and May 2018, respectively.

Under the terms of the settlement agreements and consent judgments, Par and Lupin are each prohibited from launching a generic version of OMIDRIA prior to a specified entry date. Par’s entry date is the earlier of (1) April 1, 2032 or (2) the date on which we or a third-party, through licensing or any future final legal judgment, should one ever exist, with respect to our Orange Book listed patents, is able to launch a generic version of OMIDRIA. Lupin’s entry date is the earlier of (A) April 1, 2032 if Par has forfeited its six month first-ANDA filer exclusivity, (B) October 1, 2032 if Par has not forfeited its six month first-ANDA filer exclusivity, or (C) a date on which we or a third party (other than Par), through licensing of, any future final legal judgment regarding, or the delisting, abandonment or expiration of our U.S. OMIDRIA patents, is able to launch a generic version of OMIDRIA. Under the settlement agreements, we granted each of Par and Lupin a non-exclusive, non-sublicensable license to make, sell and distribute a generic version of OMIDRIA between their applicable entry dates and the latest expiration of our U.S. patents related to OMIDRIA (i.e., October 23, 2033). During this period, Par and Lupin, as applicable, are each required to pay us a royalty equal to 15% of net sales of its generic version of OMIDRIA.

Competition

Overview. The pharmaceutical and biotechnology industry is highly competitive and characterized by a number of established, large pharmaceutical and biotechnology companies as well as smaller companies like ours. We expect to compete with other pharmaceutical and biotechnology companies, and our competitors may:

We expect to compete for market share against large pharmaceutical and biotechnology companies, smaller companies that are collaborating with larger pharmaceutical companies, new companies, academic institutions, government agencies and other public and private research organizations. In addition, the pharmaceutical and biotechnology industry is characterized by rapid technological change. Because our research approach integrates many technologies, it may be difficult for us to remain current with the rapid changes in each technology. Further, our competitors may render our technologies obsolete by advancing their existing technological approaches or developing new or different approaches. If we fail to stay at the forefront of technological change, we may be unable to compete effectively.

OMIDRIA. We are not aware of any product that directly competes with OMIDRIA and is FDA-approved for intraoperative delivery in irrigation solutions during surgical procedures; however, OMIDRIA could face competition from products that are delivered intraoperatively, but that do not include a non-steroidal anti-inflammatory agent, as well as from preoperative and postoperative treatments for mydriasis, pain or inflammation. Our primary competition for OMIDRIA comes from surgeons’ current practices, which may include use of products obtained from distributors or

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compounding pharmacies at a relatively low cost. Title I (the “Compounding Quality Act”) of the Drug Quality and Security Act, which was enacted in November 2013, added Section 503B to the FDCA establishing a distinct category of drug compounders known as “outsourcing facilities.” Among other provisions, the Compounding Quality Act imposes restrictions on the materials that may be compounded at registered outsourcing facilities and traditional compounders and places conditions on the compounding of bulk substances. Surgeons may perceive that, since the enactment of the Compounding Quality Act, compounding pharmacies, particularly those that are registered as “outsourcing facilities,” are subject to rigorous regulatory oversight that assures the safety and manufacturing quality of compounded products, notwithstanding the relatively high frequency of recall events, warning letters and findings of unsanitary conditions issued by FDA following inspection of registered outsourcing facilities. In addition, we anticipate that there are some surgeons who do not use intraoperative mydriatics and may not agree with the value proposition of maintaining pupil dilation and inhibiting miosis during the procedure, or with the use of a nonsteroidal anti-inflammatory drug intraoperatively to inhibit inflammation, prevent miosis and reduce postoperative pain. Although we are not aware of any companies developing similar approaches for maintenance of intraoperative pupil size and postoperative pain reduction as an FDA-approved product, such strategies may develop. In Europe, an inexpensive mydriatic and local anesthetic combination product is available but, unlike OMIDRIA, this product does not include an anti-inflammatory agent.

Product Candidates, Development Programs and Platforms. With respect to our development of therapeutics targeting complement-mediated disorders, there are multiple companies developing potential therapies targeting the complement system, although none of these potential therapies, to our knowledge, selectively inhibit the lectin pathway. Soliris^® (eculizumab) and Ultomiris^® (ravulizumab-cwvz) are monoclonal complement inhibitors administered intravenously and approved for commercial use with which our lead MASP-2 inhibitor, narsoplimab (OMS721), and/or our MASP-3 inhibitor OMS906 will compete, if either is approved for any indication(s) for which Soliris^® and/or Ultomiris^® are also approved. Alexion Pharmaceuticals, Inc., the manufacturer of Soliris^® and Ultomiris^®, initiated a Phase 3 trial of Ultomiris^® for HSCT-TMA in the fourth quarter of 2020.

We are aware of other companies attempting to de-orphanize orphan GPCRs. If any of these companies is able to de-orphanize an orphan GPCR before we unlock this receptor, we may be unable to establish an exclusive or commercially valuable intellectual property position around that orphan GPCR.

Intellectual Property

We have retained control of all worldwide manufacturing, marketing and distribution rights for OMIDRIA and each of our product candidates and programs. Some of our products and product candidates and programs are based on inventions and other intellectual property rights that we acquired through assignments, exclusive licenses or acquisitions described in further detail under “License and Development Agreements” below.

As of February 10, 2021, we owned or held worldwide exclusive licenses to a total of 82 issued patents and 68 pending patent applications in the U.S. and 1,161 issued patents and 582 pending patent applications in foreign markets directed to therapeutic compositions and methods related to our research and development programs. For each program, our decision to seek patent protection in specific foreign markets, in addition to the U.S., is based on many factors, including one or more of the following: our available resources, the size of the commercial market, the presence of a potential competitor or a contract manufacturer in the market and whether the legal authorities in the market effectively enforce patent rights.

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All of our employees enter into our standard employee proprietary information and inventions agreement, which includes confidentiality provisions and provides us ownership of all inventions and other intellectual property made by our employees that pertain to our business or that relate to our employees’ work for us or that result from the use of our resources. Our commercial success will depend in part on obtaining and maintaining patent protection and trade secret protection of the use, formulation and structure of our products and product candidates and the methods used to manufacture them, as well as on our ability to defend successfully these patents against third-party challenges. Our ability to protect our products and product candidates from unauthorized making, using, selling, offering to sell or importing by third parties is dependent on the extent to which we have rights under valid and enforceable patents that cover these activities.

The patent positions of pharmaceutical, biotechnology and other life sciences companies can be highly uncertain and involve complex legal and factual questions for which important legal principles remain unresolved. No consistent policy regarding the breadth of claims allowed in biotechnology patents has emerged to date in the U.S., and tests used for determining the patentability of patent claims in all technologies are in flux. The pharmaceutical, biotechnology and other life sciences patent situation outside the U.S. is even more uncertain. Changes in either the patent laws or in interpretations of patent laws in the U.S. and other countries may diminish the value of our intellectual property. Accordingly, we cannot predict the breadth of claims that may be allowed or enforced in the patents that we own or have licensed or in third-party patents.

We sell OMIDRIA under trademarks that we consider in the aggregate to be important to our operations. We have registered, and intend to maintain, the trademarks “OMEROS”, “OMIDRIA”, “OMIDRIASSURE” and “PHARMACOSURGERY” with the U.S. Patent and Trademark Office in connection with the products and services we

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offer. We are not aware of any material claims of infringement or other challenges to our right to use the “OMEROS,” “OMIDRIA,” “OMIDRIASSURE” or “PHARMACOSURGERY” trademarks in the U.S.

Government Regulation

Government authorities in the U.S., the EU and other countries extensively regulate the research, development, testing, manufacture, labeling, promotion, advertising, distribution, marketing, and export and import of drug and biologic products such as OMIDRIA and the product candidates that we are developing. Failure to comply with applicable requirements, both before and after receipt of regulatory approval, may subject us, our third-party manufacturers, and other partners to administrative and judicial sanctions, such as warning letters, product recalls, product seizures, a delay in approving or refusal to approve pending applications, civil and other monetary penalties, total or partial suspension of production or distribution, injunctions, and/or criminal prosecutions.

In the U.S., our products and product candidates are regulated by FDA as drugs or biologics under the FDCA and implementing regulations and under the Public Health Service Act (“PHSA”). In Europe, our products and product candidates are regulated by the EMA and national medicines regulators under the rules governing medicinal products in the EU as well as national regulations in individual countries. OMIDRIA has received marketing approval from FDA and from the applicable regulatory authorities in the EU. Our product candidates are in various stages of testing and none of our product candidates has received marketing approval from FDA or the applicable regulatory authorities in the EU.

The steps required before a product may be approved for marketing by FDA, or the applicable regulatory authorities outside of the U.S., typically include the following:

Manufacturing. Manufacturing of drug products for use in clinical trials must be conducted according to relevant national and international guidelines, for example, cGMP. Process and formulation development are undertaken to design suitable routes to manufacture the drug substance and the drug product for administration to animals or humans. Analytical development is undertaken to obtain methods to quantify the potency, purity and stability of the drug substance and drug product as well as to measure the amount of the drug substance and its metabolites in biological fluids, such as blood.

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Preclinical Tests. Preclinical tests include laboratory evaluations and animal studies to assess efficacy, toxicity and pharmacokinetics. The results of the preclinical tests, together with manufacturing information, analytical data, clinical development plan, and other available information are submitted as part of an IND or CTA.

The IND/CTA Process. An IND or CTA must become effective before human clinical trials may begin. INDs are extensive submissions including, among other things, the results of the preclinical tests, together with manufacturing information and analytical data. In addition to including the results of the preclinical studies, the IND will also include one or more protocols for proposed clinical trials detailing, among other things, the objectives of the clinical trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. An IND will become effective 30 days after receipt by FDA unless, before that time, FDA raises concerns or questions and imposes a clinical hold. In that event, the IND sponsor and FDA must resolve any outstanding FDA concerns or questions before the clinical hold is lifted and clinical trials can proceed. Similarly, a CTA must be cleared by the local independent ethics committee and competent authority prior to conducting a clinical trial in the country in which it was submitted. There can be no assurance that submission of an IND or CTA will result in authorization to commence clinical trials. Once an IND or CTA is in effect, there are certain reporting requirements.

Clinical Trials. Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified personnel and must be conducted in accordance with local regulations and GCPs. Clinical trials are conducted under protocols detailing, for example, the parameters to be used in monitoring patient safety and the efficacy criteria, or endpoints, to be evaluated. Each trial must be reviewed and approved by an independent institutional review board or ethics committee for each clinical site at which the trial will be conducted before it can begin. Clinical trials are typically conducted in three defined phases, but the phases may overlap or be combined:

We, our product development partners, institutional review boards or ethics committees, FDA or other regulatory authorities may suspend or terminate clinical trials at any time on various grounds, including a belief that the subjects are being exposed to an unacceptable health risk.

Disclosure of Clinical Trial Information. Sponsors of clinical trials of certain FDA-regulated products, including prescription drugs, are required to register and disclose certain clinical trial information on a public website maintained by the U.S. National Institutes of Health. Information related to the product, patient population, phase of investigation, study sites and investigator, and other aspects of the clinical trial is made public as part of the registration. Sponsors are also obligated to disclose the results of these trials after completion. Disclosure of the results of these trials can be delayed for up to two years if the sponsor certifies that it is seeking approval of an unapproved product or that it will file an application for approval of a new indication for an approved product within one year. Clinical trials conducted in European countries are required to be registered at a similar public database maintained and overseen by European health authorities. Competitors may use this publicly available information to gain knowledge regarding the design and progress of our development programs.

The Application Process. If the necessary clinical trials are successfully completed, the results of the preclinical trials and the clinical trials, together with other detailed information, including information on the manufacture and composition of the product, are submitted to FDA in the form of an NDA or a BLA, as applicable, and to the EMA or national regulators in the form of an MAA, requesting approval to market the product for a specified indication. In the EU, an MAA may be submitted to the EMA for review and, if the EMA gives a positive opinion, the EC may grant a

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marketing authorization that is valid across the EU (centralized procedure). Alternatively, an MAA may be submitted to one or more national regulators in the EU according to one of several national or decentralized procedures. The type of submission in Europe depends on various factors and must be cleared by the appropriate authority prior to submission. For most of our product candidates, the centralized procedure will be either mandatory or available as an option.

If the regulatory authority determines that the application is not acceptable, it may refuse to accept the application for filing and review, outlining the deficiencies in the application and specifying additional information needed to file the application. Notwithstanding the submission of any requested additional testing or information, the regulatory authority ultimately may decide that the proposed product is not safe or effective, or that the application does not otherwise satisfy the criteria for approval. In the U.S., to support an approval an NDA must demonstrate, among other things, that the proposed drug product is safe and effective, has a favorable benefit-risk profile, is manufactured in a way that preserves its identity, strength, purity and potency, and that its labeling is adequate and not false or misleading. A similar standard exists for BLAs. Before approving an NDA or BLA, or an MAA, FDA or the EMA, respectively, may inspect one or more of the clinical sites at which the clinical studies were conducted to ensure that GCPs were followed and may inspect facilities at which the product is manufactured to ensure satisfactory compliance with cGMP. The FDA may refer the NDA or BLA to an advisory committee for review and recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendation. In addition, even if a product candidate satisfied its endpoints with statistical significance during clinical trials, FDA could determine that the overall balance of risks and benefits for the product candidate is not adequate to support approval, or only justifies approval for a narrow set of clinical uses and/or subject to restricted distribution or other burdensome post-approval requirements or limitations. If approval is obtained changes to the approved product such as adding new indications, manufacturing changes, or additional labeling claims will require submission of a supplemental application, referred to as a variation in the EU, or, in some instances, a new application, for further review and approval. The testing and approval process requires substantial time, effort, and financial resources, and we cannot be sure that any future approval will be granted on a timely basis, if at all.

Some of our drug products may be eligible for NDA submissions to FDA for approval under the Section 505(b)(2) process. Section 505(b)(2) applications are a type of NDA that may be submitted for drug products that represent a modification, such as a new indication or new dosage form, of a previously approved drug. Section 505(b)(2) applications may rely on FDA’s previous findings for the safety and effectiveness of the previously approved drug along with additional clinical data and information obtained by the 505(b)(2) applicant to support the modification of the previously approved drug. Preparing Section 505(b)(2) applications may be less costly and time-consuming than preparing an NDA that is based entirely on new data and information.

Some of our product candidates, such as those from our MASP-2 and MASP-3 programs, are considered biologics because they are derived from natural sources as opposed to being chemically synthesized. The added complexity associated with manufacturing biologics may result in additional monitoring of the manufacturing process and product changes.

In addition, we, our suppliers and our contract manufacturers are required to comply with extensive regulatory requirements both before and after approval. For example, we must establish a pharmacovigilance system and are required to report adverse reactions and production problems, if any, to the regulatory authorities. We must also comply with certain requirements concerning advertising and promotion for our products. The regulatory authorities may impose specific obligations as a condition of the marketing authorization, such as additional safety monitoring, or the conduct of additional clinical trials or post-marketing safety studies, or the imposition of a Risk Evaluation and Mitigation Strategy (“REMS”), which could include significant restrictions on distribution or use of the product. Also, quality control and manufacturing procedures must continue to conform to cGMPs after approval. Accordingly, manufacturers must continue to expend time, money, and effort in all areas of regulatory compliance, including production and quality control to comply with cGMPs. In addition, discovery of problems such as safety issues may result in changes in labeling or restrictions on a product manufacturer or marketing authorization holder, including removal of the product from the market.

Fast-Track and Priority Review Designations. Section 506(b) of the FDCA provides for the designation of a drug as a fast-track product if it is intended, whether alone or in combination with one or more other drugs, for the treatment of a

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serious or life-threatening disease or condition, and it demonstrates the potential to address unmet medical needs for such a disease or condition. A program with fast-track status is afforded greater access to FDA for the purpose of expediting the product’s development, review and potential approval. Many products that receive fast-track designation are also considered appropriate to receive priority review, and their respective applications may be accepted by FDA as a rolling submission in which portions of an NDA or BLA are reviewed before the complete application is submitted. Together, these may reduce time of development and FDA review time. In Europe, products that are considered to be of major public health interest are eligible for accelerated assessment, which shortens the review period. The grant of fast-track status, priority review or accelerated assessment does not alter the standard regulatory requirements for obtaining marketing approval.

Breakthrough Therapy Designation. In 2012, Congress enacted the Food and Drug Administration Safety and Innovation Act. This law established a regulatory process allowing for increased interactions with FDA with the goal of expediting development and review of products designated as “breakthrough therapies.” A product may be designated as a breakthrough therapy if it is intended, either alone or in combination with one or more other products, to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The FDA may take certain actions with respect to breakthrough therapies, including holding meetings with the sponsor throughout the development process; providing timely advice to the product sponsor regarding development and approval; involving more senior staff in the review process; assigning a cross-disciplinary project lead for the review team; and taking other steps to design the clinical trials in an efficient manner.

Accelerated Approval. The FDA may grant accelerated approval to a product for a serious or life-threatening condition that provides a meaningful therapeutic advantage to patients over existing treatments based upon a determination that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit. The FDA may also grant accelerated approval for such a condition when the product has an effect on an intermediate clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality and that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. In both cases, FDA must take into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. Studies that are conducted to demonstrate a drug’s effect on a surrogate or intermediate clinical endpoint for accelerated approval must be adequate and well-controlled as required by the FDCA.

Following accelerated approval, FDA requires that the company provide confirmatory evidence, which may include certain adequate and well-controlled post-marketing clinical studies to verify and describe the clinical benefit of the product, and FDA may impose restrictions on distribution to assure safe use. Confirmatory studies are typically required to be underway at the time of the accelerated approval. If the required confirmatory studies fail to verify the clinical benefit of the drug, or if the applicant fails to perform the required confirmatory studies with due diligence, FDA may withdraw approval of the drug under streamlined procedures in accordance with the Agency’s regulations. The Agency may also withdraw approval of a drug if, among other things, other evidence demonstrates that the drug product is not shown to be safe or effective under its conditions of use.

The EU also has accelerated approval programs. In the EU, a marketing authorization may be granted on the basis of less complete data than are normally required in certain “exceptional circumstances,” such as when the product’s indication is encountered so rarely that the applicant cannot reasonably be expected to provide comprehensive data. Alternatively, a conditional marketing authorization may be granted prior to obtaining the comprehensive clinical data required for a full MAA if a product fulfills an unmet medical need and the benefit to public health of the product’s immediate availability outweighs the risk inherent in the incomplete data.

Orphan Drug Designation. Under the Orphan Drug Act (“ODA”), FDA may grant orphan drug designation to drugs or biologics intended to treat a rare disease or condition that affects fewer than 200,000 individuals in the U.S. or more than 200,000 individuals in the U.S. for which the cost of developing and making the product available in the U.S. for this type of disease or condition is not likely to be recovered from U.S. sales for that product. The granting of orphan designation does not alter the standard regulatory requirements (other than payment of certain fees and the applicability of certain pediatric assessment requirements), nor does it alter the standards or process for obtaining marketing approval.

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The sponsor of a product that has an orphan drug designation qualifies for various development incentives specified in the ODA, including a tax credit of up to 25% of expenditures on qualified clinical testing for the orphan drug. Furthermore, if the orphan designated product subsequently receives the first FDA approval for the orphan indication, the product is entitled to an orphan drug exclusivity period, which means that FDA may not grant approval to any other application to market the same drug for the same indication for a period of seven years except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity for the protected indication. Orphan drug exclusivity does not prevent FDA from approving a different drug for the same disease or condition, or the same drug for a different disease or condition. The EU has a similar Orphan Drug program to that of the U.S., and it is administered through the EMA’s Committee for Orphan Medicinal Products.

Pediatric Testing and Exclusivity. In the U.S., NDAs and BLAs are subject to both mandatory pediatric testing requirements and voluntary pediatric testing incentives in the form of exclusivity. An additional six months of exclusivity in the U.S. may be granted to a sponsor of an NDA or BLA if the sponsor conducts certain pediatric studies, which studies are conducted pursuant to a written request from FDA. This process is initiated when FDA issues a Written Request for pediatric studies to determine if the drug or biologic could have meaningful pediatric health benefits. If FDA determines that the sponsor has conducted the requested pediatric studies in accordance with the written request, then an additional six months of exclusivity may attach in the case of a drug to any other regulatory exclusivity or patent protection applicable to the drug and, in the case of a biologic, to any other regulatory exclusivity applicable to the biologic. The EU has a similar requirement and incentive for the conduct of pediatric studies according to the pediatric investigation plan, which must be adopted by the EMA before an MAA may be submitted.

Expanded Access. “Expanded access” refers to the use of an investigational drug where the primary purpose is to diagnose, monitor, or treat a patient’s disease or condition rather than to collect information about the safety or effectiveness of a drug. There are three FDA-recognized categories of expanded access trials: expanded access for individual patients, including for emergency use; expanded access for intermediate-size patient populations; and expanded access for large patient populations under a treatment IND or treatment protocol. For all types of expanded access, FDA must determine prior to authorizing expanded access that: (1) the patient or patients to be treated have a serious or life-threatening disease or condition and there is no comparable or satisfactory alternative therapy; (2) the potential patient benefit justifies the potential risks of use and that the potential risks are not unreasonable in the context of the disease or condition to be treated; and (3) granting the expanded access will not interfere with the initiation, conduct, or completion of clinical studies in support of the drug’s approval. Only a licensed physician or the drug’s manufacturer may apply for expanded access. Manufacturers are not required to supply the investigational product for expanded access. The FDA has established streamlined processes for physicians to request individual patient expanded access whereby physicians can submit a single patient IND. In cases of individual patient emergency expanded access, physicians can receive FDA approval for access by phone and follow up with the abbreviated form. In addition, the sponsor of an expanded access IND must submit IND safety reports and, in the cases of protocols continuing for one year or longer, annual reports to FDA.

U.S. Labeling, Marketing and Promotion. The FDA closely regulates the labeling, marketing and promotion of drugs. In general, our labeling and promotion must not be false or misleading in any particular, and claims that we make must be adequately substantiated. In addition, our approved labeling must include adequate directions to physicians for each intended use of our products. Failure to comply with these requirements can result in adverse publicity, warning letters, corrective advertising, injunctions and potential civil and criminal penalties.

In addition to regulation by FDA, the research, manufacturing, distribution, sale and promotion of drug products in the U.S. are subject to regulation by various federal, state and local authorities, including CMS, other divisions of the U.S. Department of Health and Human Services (e.g., the Office of Inspector General), the U.S. Department of Justice, state Attorneys General, and other state and local government agencies. All of these activities are also potentially subject to federal and state consumer protection and unfair competition laws. Violations of these laws are punishable by prison sentences, criminal fines, administrative civil money penalties, and exclusion from participation in federal healthcare programs.

There are also an increasing number of state laws that require manufacturers to make reports to states on pricing and marketing information or impose other special requirements for the sale and marketing of drug products. Many of these

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laws contain ambiguities as to what is required to comply with the laws. In addition, federal and state “transparency laws” require manufacturers to track and report certain payments made to health care providers and, under some state laws, other information concerning our products. These laws may affect our sales, marketing and other promotional activities by imposing administrative and compliance burdens on us. In addition, our reporting actions could be subject to the penalty provisions of the pertinent state and federal authorities.

Drug Supply Chain Security Act. Title II (the Drug Supply Chain Security Act (the “DSCSA”)), of the Drug Quality and Security Act imposes on manufacturers of certain pharmaceutical products new obligations related to product tracking and tracing, among others, which began a several-year phase-in process in 2015. Among the requirements of this legislation, manufacturers subject to the DSCSA are required to provide certain documentation regarding the drug product to trading partners to which product ownership is transferred, label drug product with a product identifier (i.e., serialize), respond to verification requests from trading partners, provide transaction documentation upon request by federal or state government entities, and keep certain records regarding the drug product. The transfer of information to subsequent product owners by manufacturers must be done electronically. For products and transactions falling within DSCSA’s scope, manufacturers are required to verify that purchasers of the manufacturers’ products are appropriately licensed. Further, under the DSCSA, covered manufacturers have drug product investigation, quarantine, disposition, and notification responsibilities for product that is reasonably believed or that credible evidence shows to be counterfeit, diverted, stolen, intentionally adulterated such that the product would result in serious adverse health consequences or death, the subject of fraudulent transactions or otherwise unfit for distribution such that they would be reasonably likely to result in serious health consequences or death. Anti-counterfeiting and serialization requirements similar to those under the DSCSA have also been adopted in the EU and became effective in February 2019.

Foreign Regulatory Requirements. Outside of the U.S., our ability to conduct clinical trials or market our products will also depend on receiving the requisite authorizations from the appropriate regulatory authorities. The foreign regulatory approval processes include similar requirements and many of the risks associated with FDA and/or the EU approval process described above, although the precise requirements may vary from country to country. In the EU, once an MAA is granted, the product must be “placed on the market” in at least one EEA country within three years of the date of authorization. “Placed on the market” is defined as when the medicinal product is “released into the distribution chain,” i.e., out of the direct control of the marketing authorization holder. In July 2018, we placed OMIDRIA on the market in the EU, on a limited basis, which maintained the ongoing validity of the European marketing authorization for OMIDRIA. A marketing authorization will cease to be valid if a product previously placed on the market is no longer actually present on the market for three consecutive years and we expect to make OMIDRIA available in the European market on a limited basis to the extent necessary to continue the validity of our marketing authorization.

Hatch-Waxman Act. In seeking approval for a drug through an NDA, applicants are required to list with FDA each patent with claims that cover the applicant’s drug or an approved method of use of the drug. Upon approval of a drug, each of the patents listed in the application for the drug is then published in FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Drugs listed in the Orange Book can, in turn, be cited by potential competitors in support of approval of an ANDA or a 505(b)(2) application. In this case the original NDA, i.e., the pioneer drug, is known as the “listed” drug or “reference-listed” drug. An ANDA provides for marketing of a drug that has the same active ingredients and, in some cases (e.g., ophthalmology), also the same inactive ingredients, in the same strengths, route of administration and dosage form as the listed drug and has been shown through testing to be bioequivalent to the listed drug or receives a waiver from bioequivalence testing. ANDA applicants are generally not required to conduct or submit results of preclinical or clinical tests to prove the safety or effectiveness of their drug, other than the requirement for bioequivalence testing. Drugs approved in this way are considered therapeutically equivalent, and are commonly referred to as “generic equivalents” to the listed drug. These drugs then generally can be substituted by pharmacists under prescriptions written for the original listed drug.

The ANDA or 505(b)(2) applicant is required to certify to FDA concerning any patents listed for the referenced approved drug in FDA’s Orange Book. Specifically, for each listed patent, the applicant must certify that: (1) the required patent information has not been filed; (2) the listed patent has expired; (3) the listed patent has not expired but will expire on a particular date and approval is sought after patent expiration; or (4) the listed patent is invalid, unenforceable or will not be infringed by the new drug. A certification that the new drug will not infringe the already approved drug’s listed patents or that such patents are invalid or unenforceable is called a Paragraph IV certification. If

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the ANDA or 505(b)(2) applicant does not include a Paragraph IV certification, the ANDA or 505(b)(2) application will not be approved until all of the listed patents claiming the referenced drug have expired, except for any listed patents that only apply to uses of the drug not being sought by the ANDA or 505(b)(2) applicant.

If the ANDA or 505(b)(2) applicant has made a Paragraph IV certification, the applicant must also send notice of a Paragraph IV Notice Letter to the NDA and patent holders once the ANDA or 505(b)(2) application has been accepted for filing by FDA. The NDA and patent holders may then initiate a patent infringement lawsuit in response to the notice of the Paragraph IV Notice Letter. The filing of a patent infringement lawsuit within 45 days of the receipt of notice of a Paragraph IV Notice Letter automatically prevents FDA from approving the ANDA until the earlier of 30 months, expiration of the patent, settlement of the lawsuit, modification by a court or a decision in the infringement case that is favorable to the ANDA or 505(b)(2) applicant.

The ANDA or 505(b)(2) application also will not be approved until any applicable non-patent exclusivity, such as exclusivity for obtaining approval of a new chemical entity, listed in the Orange Book for the reference-listed drug has expired. The U.S. Drug Price Competition and Patent Term Restoration Act of 1984, more commonly known as the Hatch-Waxman Act, provides a period of five years following approval of a drug containing no previously approved active moiety, during which ANDAs for generic versions of those drugs and 505(b)(2) applications referencing those drugs cannot be submitted unless the submission contains a Paragraph IV challenge to a listed patent, in which case the submission may be made four years following the original drug approval. The Hatch-Waxman Act also provides for a period of three years of exclusivity following approval of a listed drug that contains previously approved active ingredients but is approved in a new dosage form, route of administration or combination, or for a new use, the approval of which was supported by new clinical trials other than bioavailability studies that were essential to the approval and conducted by or for the sponsor. During those three years of exclusivity, FDA cannot grant approval of an ANDA or 505(b)(2) application for the protected dosage form, route of administration or combination, or use of that listed drug.

In December 2019, a piece of legislation referred to as the Creating and Restoring Equal Access to Equivalent Samples Act of 2019 (“CREATES Act”) was signed into law, which is intended to address the concern that some brand manufacturers have improperly denied generic and biosimilar product developers access to samples of brand products. The CREATES Act establishes a private cause of action that permits a generic or biosimilar product developer to sue the brand manufacturer to compel it to furnish the necessary samples on commercially reasonable, market-based terms. If the developer prevails, the court may grant the developer a monetary award up to the brand product’s revenue for the period of delay in providing samples.

Biosimilars. The enactment of federal healthcare reform legislation in March 2010 provided a new pathway for approval of follow-on biologics (i.e., biosimilars) under the PHSA. FDA licensure of a biosimilar is dependent upon many factors, including a showing that the proposed biosimilar is “highly similar” to the reference product, notwithstanding minor differences in clinically inactive components, and has no clinically meaningful differences from the reference product in terms of safety, purity, and potency. The types of data ordinarily required in a biosimilar application to show high similarity include analytical data, animal studies (including toxicity studies), and clinical studies (including immunogenicity and pharmacokinetic/pharmacodynamic studies). A biosimilar must seek licensure for a condition of use for which the reference-listed product is licensed.

Furthermore, the PHSA provides that for a biosimilar to be considered “interchangeable” (i.e., the biological product may be substituted for the reference product without the intervention of the health care provider who prescribed the reference product), the applicant must make an additional showing that the biosimilar can be expected to produce the same clinical result as the reference product in any given patient, and if the product is administered more than once to a patient, that risks in terms of safety or diminished efficacy of alternating or switching between the biological product and the reference product is no greater than the risk of using the reference product without switching. Although FDA has provided guidance on what information and data an applicant should submit to enable an interchangeability determination, thus far FDA has not licensed any biologic as being interchangeable with its reference product.

The PHSA also provides a period of exclusivity for pioneer biologics. Specifically, FDA may not accept a biosimilar application referencing data from a pioneer biologic (i.e., one approved through a full BLA) until four years have elapsed from the date of first licensure of the pioneer biologic. FDA may not approve a biosimilar application

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referencing data from a pioneer biologic until 12 years have elapsed since the date of first licensure of the pioneer biologic. There are certain restrictions and limitations on the types of BLAs that are eligible for biologics exclusivity as well as what constitutes the date of first licensure for a pioneer biologic.

In the EU, a pathway for the approval of biosimilars has existed since 2005.

Healthcare compliance laws. In the U.S., commercialization of OMIDRIA and our product candidates, if approved, is subject to regulation and enforcement under a number of federal and state healthcare compliance laws administered and enforced by various agencies. These include, but are not limited to, the following:

In addition to these federal law requirements, several U.S. states have enacted similar laws requiring periodic reporting and/or disclosure related to our marketing, sales and other activities, or regulating certain sales and marketing activities, such as provision of meals, gifts or entertainment to certain health care providers. We may also be subject to federal or state privacy laws if we receive protected patient health information.

Similar requirements apply to our operations outside of the U.S. Laws in the U.S. such as the Foreign Corrupt Practices Act prohibit the offering or payment of bribes or inducements to foreign public officials for business, including physicians or other medical professionals who are employees of public healthcare entities. In addition, many non-U.S. jurisdictions in which we operate, or may operate in the future, have their own laws similar to the healthcare compliance laws that exist in the U.S.

Pharmaceutical Pricing and Reimbursement

Overview. In both U.S. and foreign markets, our ability to commercialize our products and product candidates successfully, and to attract commercialization partners for our products and product candidates, depends in significant part on the availability of adequate financial coverage and reimbursement from third-party payers including, in the U.S., managed care organizations and other private health insurers as well as governmental payers such as the Medicare and Medicaid programs. Reimbursement by a third-party payer may depend on a number of factors, including the payer’s determination that use of a product is:

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Reimbursement by government payers is based on statutory authorizations and complex regulations that may change with annual or more frequent rulemaking, as well as legislative reform measures.

Third-party private and governmental payers are increasingly challenging the prices charged for medicines and examining their cost-effectiveness in addition to their safety and efficacy. We may need to conduct expensive pharmacoeconomic studies in order to demonstrate the cost effectiveness of our products or product candidates. Even with the availability of such studies, third-party private and/or governmental payers may not provide coverage and reimbursement for our products or product candidates, in whole or in part.

United States. Political, economic and regulatory influences are subjecting the healthcare industry in the U.S. to fundamental changes. There have been, and we expect there will continue to be, legislative and regulatory proposals to change the healthcare system in ways that could significantly affect our business. For example, the 2010 Affordable Care Act (the “ACA”), is intended to broaden access to health insurance, reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add transparency requirements for the healthcare and health insurance industries, impose new taxes and fees on the health industry and impose additional health policy reforms. Other legislative changes included a two percent across-the-board reduction to Medicare payments to providers, effective April 1, 2013, which, due to subsequent legislative amendments, will stay in effect through fiscal year 2029 unless additional congressional action is taken. (A temporary suspension of this reduction during the public health emergency for the pandemic is currently scheduled to expire on March 31, 2021.) The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several providers, and increased the period for the government to recover overpayments to providers from three to five years. In December 2017, portions of the ACA dealing with the individual mandate insurance requirement were effectively repealed by the Tax Cuts and Jobs Act of 2017. In December 2018, a federal district court judge in Texas found the ACA’s individual mandate to be unconstitutional and, therefore, the entire law to be invalid. In December 2019, the Fifth Circuit affirmed the ruling regarding the individual mandate but remanded the case to the district court for additional analysis of the question of severability and whether portions of the law remain valid. The case is currently pending at the Supreme Court, and a decision is expected by mid-2021.

In November 2020, CMS issued an interim final rule through the CMS Innovation Center whereby Medicare Part B reimbursement for “certain high-cost prescriptions drugs” would be no more than most-favored-nation price (i.e., the lowest price) after adjustments, for a pharmaceutical product that the drug manufacturer sells in a member country of the Organization for Economic Cooperation and Development that has a comparable per-capita gross domestic product. In December 2020, the United States District Court in Northern California issued a nationwide preliminary injunction against implementation of the interim final rule. The incoming Biden administration has indicated that lowering prescription drug prices is a priority, but it is not yet clear what steps the administration will take or whether such steps will be successful. We cannot predict the ultimate content, timing or effect of any healthcare reform legislation or executive order or the impact that the resulting changes may have on us.

We are unable to predict what additional legislation, regulations, policies or court orders, if any, relating to the healthcare industry or coverage and reimbursement may be enacted or imposed in the future or what effect such legislation, regulations, policies or court orders would have on our business. Any cost-containment measures, including those listed above, or other healthcare system reforms that are adopted could have a material adverse effect on our business prospects and financial operations.

Europe. Governments in the various member states of the EU influence or control the price of medicinal products in their countries through their pricing and reimbursement rules and control of national healthcare systems that fund a large part of the cost of those products to consumers. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical trials or pharmacoeconomic studies that assess the cost-effectiveness of a product or product candidate relative to currently available therapies or relative to a specified standard. The downward pressure on healthcare costs in general, and prescription medicines in particular, has become very intense and is creating increasingly high barriers to the entry of new products in these markets.

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Research and Development

We have built a research and development organization that includes expertise in discovery research, preclinical development, product formulation, analytical and medicinal chemistry, manufacturing, clinical development and regulatory and quality assurance. We operate cross-functionally and are led by an experienced management team. We use rigorous project management techniques to make disciplined strategic decisions regarding our research and development programs and to limit the risk profile of our product pipeline. We also access relevant market information and key opinion leaders in creating target product profiles and, when appropriate, as we advance our programs to commercialization. We engage third parties on a limited basis to conduct portions of our preclinical research; however, we are not substantially dependent on any third parties for our preclinical research nor do any of these third parties conduct a major portion of our preclinical research. We also engage multiple clinical sites to conduct our clinical trials. None of these sites conduct the major portion of our clinical trials and we are not substantially dependent on any one of them.

Employees

As of December 31, 2020, we had 277 full-time employees, 145 of whom are in research and development, 81 of whom are in sales and marketing and 51 of whom are in finance, legal, business development and administration. Our full-time employees include eight with M.D.s and 38 with Ph.Ds., of whom one and 22, respectively, are in research and development. None of our employees is represented by a labor union, and we consider our employee relations to be good.

Information about Our Executive Officers and Significant Employees

The following table provides information regarding our executive officers and significant employees as of March 1, 2021:

​

Gregory A. Demopulos, M.D. founded our company and has served as our president, chief executive officer and chairman of the board of directors since June 1994. He also served as our chief financial officer and treasurer from January 2009 to October 2013 in an interim capacity and as our chief medical officer from June 1994 to March 2010. Prior to founding Omeros, Dr. Demopulos completed his residency in orthopedic surgery at Stanford University and his fellowship training in hand and microvascular surgery at Duke University. Dr. Demopulos currently serves on the board of trustees of the Smead Funds Trust, an open-end mutual fund company registered under the Investment Company Act of 1940. Dr. Demopulos received his M.D. from the Stanford University School of Medicine and his B.S. from Stanford University. Dr. Demopulos is the brother of Peter A. Demopulos, M.D., a member of our board of directors.

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Michael A. Jacobsen has served as our vice president, finance, chief accounting officer and treasurer since October 2013. Prior to joining Omeros, Mr. Jacobsen served as vice president of finance of Sarepta Therapeutics, Inc. from September 2011 to May 2013 and as its chief accounting officer from September 2011 to December 2012. From April 2007 to August 2011, Mr. Jacobsen was vice president and chief accounting officer at ZymoGenetics, Inc. Prior to his service with ZymoGenetics, Mr. Jacobsen held various roles at ICOS Corporation, including senior director of finance and corporate controller. From April 1995 to October 2001, Mr. Jacobsen held vice president of finance or chief financial officer roles at three companies in the software, computer hardware and internet retailing industries, two of which were publicly traded. Mr. Jacobsen is a certified public accountant and received his bachelor’s degree in accounting from Idaho State University.

Peter B. Cancelmo, J.D. has served as our vice president, general counsel and secretary since June 2019. He joined Omeros as deputy general counsel, corporate governance and securities in January 2019. Prior to joining Omeros, Mr. Cancelmo was a principal and shareholder at Garvey Schubert Barer, P.C., where he represented clients in the life sciences and other technology industries in mergers, acquisitions, strategic alliances, public and private securities offerings, and a range of other corporate, commercial and financial transactions. He served as chair of the firm’s business practice group from 2016 until his departure in December 2018. Mr. Cancelmo previously practiced corporate and transactional law at Davies, Ward, Philips and Vineberg LLP, in New York, and Choate, Hall & Stewart LLP, in Boston. Mr. Cancelmo received his J.D. from Boston University and his B.A. from Saint Michael’s College.

Christopher S. Bral, Ph.D. has served as our vice president, nonclinical development since October 2015. From April 2014 to October 2015, Dr. Bral was the executive director, toxicology at Arrowhead Research Corporation, a biopharmaceutical company. From June 2008 to April 2014, Dr. Bral served as director, drug safety evaluation at Vertex Pharmaceuticals, a biotechnology company. Prior to Vertex, Dr. Bral held various pre-clinical drug safety positions of increasing responsibility at Schering-Plough Research Institute including associate director, drug safety evaluation. Dr. Bral received his Ph.D. in biochemistry and biophysics from Texas A&M University and his B.S. in chemistry from John Carroll University. He has been board-certified in toxicology through the American Board of Toxicology since 2000.

Nadia Dac has served as our Chief Commercial Officer since January 2021. Ms. Dac brings nearly three decades of international experience as a strategic commercial leader at large and small biopharmaceutical companies. Prior to joining Omeros, Ms. Dac served as the chief commercial officer at Alder Pharmaceuticals, Inc. (acquired in 2019 by Lundbeck) from April 2019 until June 2020 and as vice president of global specialty commercial development at AbbVie, Inc. from December 2014 to March 2019. She previously served as vice president of marketing at Auxilium Pharmaceuticals, Inc. from May 2013 to September 2014, when the company was acquired by Endo International plc. From 2009 to 2013, Ms. Dac held several roles of increasing responsibility at Novartis AG, including global vice president of neuroscience professional relations prior to her role as vice president of Novartis’ multiple sclerosis franchise, and at Biogen Inc., Johnson & Johnson, and Eli Lilly and Company. She holds a B.S. in Marketing from Rutgers University.

Timothy M. Duffy has served as our vice president, business development since March 2010. From November 2008 to March 2010, Mr. Duffy served as the managing director of Pacific Crest Ventures, a life science consulting firm that he founded. From June 2004 through September 2008, Mr. Duffy served at MDRNA, Inc. (formerly Nastech Pharmaceutical Company, Inc.), a biotechnology company. At MDRNA, he held roles of increasing responsibility in marketing and business development, most recently as the chief business officer. Prior to MDRNA, Mr. Duffy served as vice president, business development at Prometheus Laboratories, Inc., a specialty pharmaceutical company, and as a customer marketing manager at The Procter & Gamble Company. Mr. Duffy received his B.S. from Loras College.

George A. Gaitanaris, M.D., Ph.D. has served as our vice president, science since August 2006 and as our chief scientific officer since January 2012. From August 2003 until our acquisition of nura, inc., in August 2006, Dr. Gaitanaris served as the chief scientific officer of nura, a company that he co-founded, and that developed treatments for central nervous system disorders. From 2000 to 2003, Dr. Gaitanaris served as president and chief scientific officer of Primal, Inc., a biotechnology company that was acquired by nura in 2003. Prior to co-founding Primal, Dr. Gaitanaris served as staff scientist at the National Cancer Institute. Dr. Gaitanaris received his Ph.D. in cellular, molecular and

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biophysical studies and his M.Ph. and M.A. from Columbia University and his M.D. from the Aristotelian University of Greece.

Bruce Meiklejohn, Ph.D. has served as our vice president, chemistry, manufacturing and controls (“CMC”) since October 2019. Prior to joining Omeros in this role, Dr. Meiklejohn was an expert CMC consultant for several biotechnology companies, including Omeros. His consulting work followed a career of over 27 years at Eli Lilly and Company, where he held a number of CMC leadership roles including head of Lilly’s biopharmaceutical product development division and senior research fellow in regulatory affairs CMC. While at Lilly, Dr. Meiklejohn led or played a key role in CMC activities for a number of multibillion-dollar drugs, including Trulicity^®, Cialis^®, Alimta^®, Forteo^®, and Cymbalta^®. Dr. Meiklejohn earned his Ph.D. in analytical chemistry and his B.S. in biology and chemistry at Colorado State University.

Catherine A. Melfi, Ph.D. has served as our vice president, regulatory affairs and quality systems since October 2012 and has served as our chief regulatory officer since April 2016. Dr. Melfi previously served from January 1996 to September 2012 at Eli Lilly and Company, where she held technical and leadership roles of increasing scope and responsibility, including as senior director and scientific director in global health outcomes and regulatory affairs, respectively. Prior to joining Eli Lilly, Dr. Melfi held various faculty and research positions at Indiana University, including appointments in its Economics Department, in the School of Public and Environmental Affairs, and in the Indiana University School of Medicine. Dr. Melfi received her Ph.D. in Economics from the University of North Carolina - Chapel Hill and B.S. in Economics from John Carroll University.

Tina Quinton, J.D., M.S. has served as our vice president, patents, since June 2019 and previously served as our deputy general counsel, patents from August 2017 to June 2019 and as associate general counsel, patents from 2012 to 2017. Prior to joining Omeros, Ms. Quinton was a partner with the firm Christensen O'Connor Johnson & Kindness, PLLC, where she represented clients in the biotechnology and medical sciences industries in all aspects of worldwide patent procurement and enforcement. Before Christensen O'Connor Johnson & Kindness, Ms. Quinton was a research scientist at several biotechnology companies and centers, including ZymoGenetics, Targeted Genetics Corporation and Fred Hutchinson Cancer Research Center. Ms. Quinton received her J.D. and her M.S. in Molecular and Cellular Biology from the University of Washington and her B.S. from Gordon College.

J. Steven Whitaker, M.D., J.D. has served as our vice president, clinical development since joining Omeros in 2010, and served as our chief medical officer from March 2010 to August 2018 and since November 2019. From May 2008 to March 2010, Dr. Whitaker served as the chief medical officer, vice president of clinical development at Allon Therapeutics, Inc., a biotechnology company focused on developing drugs for neurodegenerative diseases. From August 2007 to May 2008, he served as a medical consultant to Accelerator Corporation, a biotechnology-company investor and incubator. From May 1994 to May 2007, Dr. Whitaker served at ICOS Corporation, which was acquired by Eli Lilly and Company in 2007. At ICOS, he held roles of increasing responsibility in clinical research and medical affairs, most recently as divisional vice president, clinical research as well as medical director of the Cialis^® global product team. Dr. Whitaker received his M.D. from the Indiana University School of Medicine, his J.D. from the University of Washington and his B.S. from Butler University.

Peter W. Williams has served as our vice president, human resources since June 2020. Prior to joining Omeros, Mr. Williams served as the senior vice president of human resources at Redbox Automated Retail, LLC from 2016 to 2019, where he led human resources and internal communications functions. From 2013 to 2016, Mr. Williams served as the vice president, HR operations at Outerwall Inc. (Coinstar) and before that he held human resources leadership roles at Coinstar from 2009 to 2013. Prior to 2009, Mr. Williams held human resources leadership roles at various technology and consumer focused companies, including Washington Mutual, Inc., Sterling Commerce, Inc., Expedia, Inc., and Verio, Inc. Mr. Williams received a B.A. in Business Administration and a B.A. in English from the University of Washington.

Corporate Information

We were incorporated in 1994 as a Washington corporation. Our principal executive offices are located at 201 Elliott Avenue West, Seattle, Washington, 98119, and our telephone number is (206) 676-5000. Our website address is

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www.omeros.com. We make available, free of charge through our investor relations website at investor.omeros.com, our annual report on Form 10-K, our quarterly reports on Form 10-Q, our current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, including exhibits to those reports, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. Our websites and the information contained therein or incorporated therein are not intended to be incorporated into this Annual Report on Form 10-K. The SEC maintains a website that contains reports, proxy and information statements, and other information regarding reports that we file or furnish electronically with them at www.sec.gov.

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SUMMARY RISK FACTORS

The risk factors described below are a summary of the principal risk factors associated with an investment in our company. These are not the only risks we face. You should carefully consider the risk factors discussed in this summary, as well as the risk factors described in Item 1A. of this Annual Report on Form 10-K.

Risks related to our products, programs and operations include, but are not limited to, the following:

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General risks related to our business include the following:

ITEM 1A.            RISK FACTORS

The risks and uncertainties described below may have a material adverse effect on our business, prospects, financial condition or operating results. In addition, we may be adversely affected by risks that we currently deem immaterial or by other risks that are not currently known to us. You should carefully consider these risks before making an investment decision. The trading price of our common stock could decline due to any of these risks and you may lose all or part of your investment. In assessing the risks described below, you should also refer to the other information contained in this Annual Report on Form 10-K.

Risks Related to Our Products, Programs and Operations

Our ability to achieve profitability is highly dependent on the commercial success of OMIDRIA, and to the extent OMIDRIA is not successful, our business, financial condition and results of operations may be materially adversely affected and the price of our common stock may decline.

OMIDRIA is currently our only product that has been approved by FDA for commercial sale in the U.S. For the three and 12 months ended December 31, 2020, we recorded net sales of OMIDRIA of $10.6 million and $73.8 million, respectively. Revenues from sales of OMIDRIA have not been sufficient to fund our operations fully in prior periods and we cannot provide assurance that revenues from OMIDRIA sales will be sufficient to fund our operations fully in the future. We will need to generate substantially more product revenue from OMIDRIA or generate other revenue such as through sales of future approved products to achieve and sustain profitability. We may be unable to sustain or increase revenues generated from OMIDRIA product sales for a number of reasons, including:

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Clinical trials evaluating narsoplimab for treatment of COVID-19 may be unsuccessful and, even if successful, we may be unable to manufacture narsoplimab in quantities adequate to meet demand.

Narsoplimab has been used to treat approximately 20 critically ill COVID-19 patients under our compassionate use program with highly positive results. However, we cannot provide assurance that the results observed in the compassionate use program will be observed in any future study of narsoplimab for this indication, including the I-SPY COVID-19 trial, or that we will receive regulatory authorization or approval for narsoplimab in the treatment of COVID-19 patients.

Narsoplimab or any other therapeutic candidate that we may develop to treat COVID-19 will be subject to risks in addition to those normally associated with pharmaceutical research, development, and commercialization, such as higher risk of technical failure, lower and transient opportunities for revenue, higher manufacturing costs, product safety or efficacy risks related to an expedited research and development timeline, and novel liability theories. FDA or other regulatory bodies may require that we conduct a large-scale trial of narsoplimab in COVID-19 patients, in addition to the I-SPY COVID-19 trial to grant any approval or authorization. These risks may affect our ability to develop or commercialize a therapeutic for COVID-19 or any other current or future indication.

Additionally, contract manufacturing capacity and supplies of raw materials necessary for the production of narsoplimab are limited and we may be unable to secure the large-scale manufacturing capacity from third parties necessary to manufacture narsoplimab in sufficient quantities to enable broader availability of narsoplimab for COVID-19 patients. In addition, widespread vaccination and/or the availability of alternative therapies for COVID-19 could lead to the diversion of governmental and other potential sources of funding or other manufacturing assistance away from us and toward COVID-19 vaccines or other therapeutics and/or limit the commercial viability of narsoplimab for the treatment of COVID-19.

The spread of COVID-19 and efforts to reduce its transmission may negatively impact our business, operations and financial results.

The COVID-19 pandemic has significantly affected the global economy and has adversely affected our sales of OMIDRIA due to a reduction in the overall volume of cataract surgery and intraocular lens replacement procedures. Although cataract surgeries have resumed to varying degrees in locations throughout the country, if the number of cataract procedures once again becomes meaningfully limited, either by necessity for time-consuming safety protocols, reduction in patient demand, or the imposition of prohibitions on elective surgeries in some localities, then we would expect there to be a corresponding reduction in demand for OMIDRIA.

We may also experience disruptions to our operations due to COVID-19, such as delays or disruptions with respect to manufacturing of clinical or commercial drug substance or drug product and delays in our clinical trials or in the submission or review of regulatory applications. Such delays or disruptions could negatively affect our commercial operations, clinical programs, and research and development. The health of our employees, contractors and other persons on whom we rely may be adversely affected by COVID-19. Although we are taking precautionary measures intended to help minimize the risk of the virus to our employees, these measures may be ineffective or may otherwise adversely

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affect our productivity. In addition, the conditions created by the pandemic may intensify other risks inherent in our business. Due to the unknown magnitude, duration and outcome of the COVID-19 pandemic, it is not possible to estimate precisely its impact on our business, operations or financial results; however, the impact could be material.

To the extent COVID-19 adversely affects our business, financial condition, and results of operations and global economic conditions more generally, it may also have the effect of heightening many of the other risk factors set forth herein..

If OMIDRIA or any other product that we develop and commercialize does not receive adequate coverage or reimbursement from governments and/or private payers, or if we do not establish and maintain market-acceptable pricing for OMIDRIA or those potential other commercialized products, our prospects for revenue and profitability would suffer.

Our revenues depend heavily on the pricing, availability and duration of adequate coverage or reimbursement for the use of products that we or our third-party business partners commercialize, including OMIDRIA, from government, private and other third-party payers, both in the U.S. and in other countries.

Pass-through reimbursement, which allows for separate payment (i.e., outside the packaged payment rate for the surgical procedure) under Medicare Part B, expired for OMIDRIA on October 1, 2020. In December 2020, CMS confirmed that OMIDRIA qualifies for separate payment when used on Medicare Part B patients in the ASC setting under CMS’ policy for non-opioid pain management surgical drugs. CMS made separate payment for OMIDRIA effective retroactively as of October 1, 2020. CMS’ current non-opioid separate payment policy and, as a result, separate payment for OMIDRIA thereunder, like other CMS policies in the OPPS and ASC systems, can be changed by CMS through its OPPS/ASC annual rulemaking and comment process. We believe that CMS will continue its separate payment policy for non-opioid pain management surgical drugs, which has been in effect since 2019, and that OMIDRIA will continue to be separately reimbursed when used in the ASC setting. However, we can provide no guarantee that CMS will continue its separate payment policy in future years. If the future reimbursement status of OMIDRIA continues to be uncertain, then demand for OMIDRIA from ASCs and hospitals may be reduced substantially. In such event, sales to our wholesalers may decrease correspondingly, as they adjust on-hand inventory in anticipation of reduced demand from end users.

There may be significant delays in obtaining coverage or reimbursement for newly approved products, and we may not be able to provide data sufficient to be granted adequate coverage or reimbursement. Even when a payer determines that a product is eligible for reimbursement, coverage may be limited to the uses of a product that are either approved by FDA (or, in other countries, the relevant country’s regulatory agency) and/or appear in a recognized drug compendium, or other conditions may apply. Moreover, eligibility for coverage does not mean that any product will be reimbursed at a rate that allows us to make a profit in all cases or at a rate that covers our costs, including research, development, manufacturing, sales and distribution. Increasingly, government and private third-party payers that reimburse for healthcare services and products are requiring that companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products, which could adversely impact the pricing of our products. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payers. Pricing may also be adversely affected by changes in the terms, scope and/or complexity of government pricing requirements. Even if we achieve coverage or reimbursement for a product, the initial rate or method at which the product will be reimbursed could become unfavorable to us at the time reimbursement is initiated or in the future or may be of a limited duration. In addition, obtaining acceptable coverage and reimbursement from one payer does not guarantee that we will obtain similar acceptable coverage or reimbursement from another payer.

In non-U.S. jurisdictions, we must obtain separate reimbursement approvals and comply with related foreign legal and regulatory requirements. In some countries, including those in the EU, our products may be subject to government price controls. Pricing negotiations with governmental authorities can take a considerable amount of time and expenditure of resources after the receipt of marketing approval for a product. We provide no assurances that the price of any product in one or more of these countries or regions will allow us to make a profit or cover our costs, including research, development, manufacturing, sales and distribution, and as a result we may decide to delay, potentially indefinitely, initiating sales in the particular country or region.

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If the reimbursement or pricing that we are able to obtain and maintain for any product that we develop and commercialize, including OMIDRIA, is inadequate, is significantly delayed or is subject to overly restrictive conditions, our ability to generate revenue, attain profitability and/or commercialize our product candidates may be impaired and there could be a material adverse effect on our business, financial condition, results of operations and growth prospects and trading price of our stock could decline.

Failure to obtain and maintain regulatory approval in the U.S. or in foreign jurisdictions would prevent us from marketing our current and future products.

Our BLA for narsoplimab for the treatment of HSCT-TMA is under priority review by FDA. The regulatory process is subject to substantial agency discretion and risks, including those described herein and elsewhere in these “Risk Factors.” FDA may require additional data regarding narsoplimab or HSCT-TMA for any reason, which could delay or require a resubmission our BLA, or FDA may approve narsoplimab for a much narrower indication or patient population than we have requested and/or with significant restrictions on distribution or use, including through a REMS. Ultimately, we cannot guarantee that FDA will ever approve narsoplimab for the treatment of HSCT-TMA or any other indication.

We also intend to have OMIDRIA and our current and future product candidates, if approved, marketed outside the U.S. In order to market our products in non-U.S. jurisdictions, we or our partners must obtain separate regulatory approvals and comply with numerous and varying regulatory requirements. The regulatory approval procedure varies among countries and can involve additional testing and data review. The requirements governing marketing authorization, the conduct of clinical trials, pricing and reimbursement vary from country to country. Approval by FDA does not ensure approval by the EMA, and approval by one foreign regulatory authority does not ensure approval by regulatory agencies in other foreign countries or by FDA. The time required to obtain regulatory approval outside the U.S. and EU may differ from that required to obtain FDA or EU approval. The foreign regulatory approval process may include all of the risks associated with obtaining FDA approval discussed in these “Risk Factors” and we may not obtain foreign regulatory approvals on a timely basis, or at all. In addition, even if we were able to obtain regulatory approval for a product in one or more foreign jurisdictions, we may need to complete additional requirements to maintain that approval and our ability to market the product in the applicable jurisdiction.

Our operating results are unpredictable and may fluctuate.

Our operating results are difficult to predict and will likely fluctuate from quarter to quarter and year to year. We believe that our quarterly and annual results of operations may be affected by a variety of factors, including:

In addition, the number of procedures or cases in which OMIDRIA or any of our product candidates, if commercialized, would be used may be significantly less than the total number of such procedures performed or total possible market size. These and other factors, including multiple changes in the reimbursement status for OMIDRIA since initially approved, make it difficult for us to forecast and provide accurate guidance (including updates to prior

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guidance) related to our expected financial performance. If our operating results are below the expectations of securities analysts or investors, the trading price of our stock could decline.

We have incurred cumulative operating losses since inception. If we are unable to raise additional capital when needed, our commercial operations may be limited and we may be unable to complete the development and commercialization of our product candidates or to continue our other preclinical development programs.

Our operations have consumed substantial amounts of cash since our incorporation and, as of December 31, 2020, we had an accumulated deficit of approximately $872.7 million. We expect to continue to spend substantial amounts to:

We expect to continue to incur additional losses until such time as we generate significant revenue from the sale of OMIDRIA, other commercial products or partnerships. We are unable to predict the extent of any future losses and cannot provide assurance that we will generate sufficient revenue from OMIDRIA or other commercial products in the future to fund our operations fully. If we are unable to generate sufficient revenue from the sale of OMIDRIA, other commercialized products or partnership arrangements, we may never become and remain profitable and will be required to raise additional capital to continue to fund our operations. We cannot be certain that additional capital will be available to us on acceptable terms, if at all, when required. Adverse developments to our financial condition or business, as well as disruptions in the global equity and credit markets, may limit our ability to access capital. If we do not raise additional capital when needed through one or more funding avenues, such as debt or equity financings or corporate partnering, we may have to significantly delay, scale back or discontinue the development or commercialization of one or more of our product candidates or one or more of our preclinical programs or other research and development initiatives. In addition, we may be required to seek collaborators for one or more of our current or future products at an earlier stage than otherwise would be desirable or on terms that are less favorable than otherwise might be available or to relinquish or license on unfavorable terms our rights to technologies or products that we otherwise would seek to develop or commercialize ourselves. We also may have insufficient funds or otherwise be unable to advance our preclinical programs, such as potential new drug targets developed from our GPCR program, to a point where they can generate revenue through partnerships, collaborations or other arrangements. Any of these actions could limit the amount of revenue we are able to generate and harm our business and prospects.

We are subject to extensive government regulation and the failure to comply with these regulations may have a material adverse effect on our operations and business.

Both before and after approval of any product, we and our suppliers, contract manufacturers and clinical investigators are subject to extensive regulation by governmental authorities in the U.S. and other countries, covering, among other things, testing, manufacturing, quality control, clinical trials, post-marketing studies, reporting, risk management plans, labeling, advertising, promotion, distribution, import and export, governmental pricing, price reporting and rebate requirements. Failure to comply with applicable requirements could result in one or more of the following actions: warning letters; unanticipated expenditures; delays in approval or refusal to approve a product candidate; product recall or seizure; interruption of manufacturing or clinical trials; operating or marketing restrictions; injunctions; criminal prosecution and civil or criminal penalties including fines and other monetary penalties; adverse publicity; and disruptions to our business. Further, government investigations into potential violations of these laws

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would require us to expend considerable resources and face adverse publicity and the potential disruption of our business even if we are ultimately found not to have committed a violation.

Obtaining FDA approval of our product candidates requires substantial time, effort and financial resources and may be subject to both expected and unforeseen delays, and there can be no assurance that any approval will be granted on any of our product candidates on a timely basis, if at all. Even if we discuss with, and obtain feedback from, FDA regarding our proposed clinical trials, clinical data collection protocols and nonclinical studies before initiating those trials or studies, FDA may decide that the design of our clinical trials or clinical data collection protocols as actually run, or our resulting data, are insufficient for approval of our product candidates and may require us to run additional preclinical, clinical or other studies or perform additional work related to chemistry, manufacturing and controls. In addition, we, FDA or an independent institutional review board or ethics committee may suspend or terminate human clinical trials at any time on various grounds, including a finding that the patients are or would be exposed to an unacceptable health risk or because of the way in which the investigators on whom we rely carry out the trials. We are subject to extensive government regulation of the testing of our investigational products, including the requirement that we conduct all of our clinical trials in accordance with FDA’s GCP requirements and similar requirements outside of the United States. If we are unable to comply with these requirements, if we are required to conduct additional trials or to conduct other testing of our product candidates beyond that which we currently contemplate for regulatory approval, if we are unable to complete our clinical trials or other testing successfully, or if the results of these and other trials or tests fail to demonstrate efficacy or raise safety concerns, we may face substantial additional expenses, be delayed in obtaining marketing approval for our product candidates or may never obtain marketing approval.

We are also required to comply with extensive governmental regulatory requirements after a product has received marketing authorization. Governing regulatory authorities may require post-marketing studies that may negatively impact the commercial viability of a product. Once on the market, a product may become associated with previously undetected adverse effects and/or may develop manufacturing difficulties. We are required to comply with other post-marketing requirements including current Good Manufacturing Practices, advertising and promotion restrictions, pharmacovigilance requirements including risk management activities, reporting and recordkeeping obligations, and other requirements. As a result of any of these or other problems or failure to comply with our regulatory obligations, a product’s regulatory approval could be withdrawn, which could harm our business and operating results. In addition, we must maintain an effective healthcare compliance program in order to comply with U.S. and other laws applicable to marketed drug products and, in particular, laws (such as the Anti-Kickback Statute, the False Claims Act and the Sunshine Act) applicable when drug products are purchased or reimbursed by a federal or state healthcare program. U.S. laws such as the Foreign Corrupt Practices Act prohibit the offering or payment of bribes or inducements to foreign public officials, including potentially physicians or other medical professionals who are employees of public healthcare entities in jurisdictions outside the U.S. In addition, many countries have their own laws similar to the healthcare compliance laws that exist in the U.S. Implementing and maintaining an effective compliance program requires the expenditure of significant time and resources. If we are found to be in violation of any of these laws, we may be subject to significant penalties, including but not limited to civil or criminal penalties, damages and fines as well as exclusion from government healthcare programs.

We may face difficulties from changes to current regulations as well as future legislation.

Existing regulatory policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the U.S. or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability.

There is uncertainty with respect to the impact that healthcare reform legislation and the policies of the Biden administration may have on coverage and reimbursement for healthcare items and services covered by plans that are authorized by the ACA. We expect that the ACA, if it remains in effect, as well as other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and apply downward pressure on the price that we receive for any approved product. Any reduction in reimbursement from Medicare or other government

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programs may result in a similar reduction in payments from private payers. If the ACA were to be invalidated by the Supreme Court or repealed, any resulting reduction in the percentage of the U.S. population that has healthcare insurance could reduce the market for our products. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate sufficient revenue, attain and/or maintain profitability or commercialize our product candidates. We cannot be sure whether additional legislative changes will be enacted, or whether FDA regulations, guidance or interpretations will be changed, or what the impact of such changes on OMIDRIA or the marketing approvals of our product candidates, if any, may be.

We have no internal capacity to manufacture commercial or clinical supplies of OMIDRIA or our product candidates and intend to continue to rely solely on third-party manufacturers. If the contract manufacturers that we rely on experience difficulties manufacturing and supplying OMIDRIA or our product candidates, or fail FDA or other regulatory inspections, our clinical trials, regulatory submissions and ability to sell OMIDRIA or any other commercialized product and generate revenue may be significantly limited or delayed.

We rely and intend to continue to rely on third-party manufacturers to produce commercial quantities of OMIDRIA and clinical drug supplies of our product candidates that are needed for clinical trials and to support NDAs, BLAs, or similar applications to regulatory authorities seeking marketing approval for our product candidates, as well as to produce inventory of our product candidates for commercial use in anticipation of marketing approval. We cannot provide any assurance that we will be able to enter into or maintain these types of arrangements on commercially reasonable terms, or at all. If we or one of our manufacturers were to terminate one of these arrangements early, or the manufacturer was unable to supply product quantities sufficient to meet our requirements, we would be required to transfer manufacturing to an approved alternative facility and/or establish additional manufacturing and supply arrangements. We may also need to establish additional or replacement manufacturers, potentially with little or no notice, in the event that one of our manufacturers fails to comply with FDA and/or other pharmaceutical manufacturing regulatory requirements. Even if we are able to establish additional or replacement manufacturers, identifying these sources and entering into definitive supply agreements and obtaining regulatory approvals may require a substantial amount of time and cost and may create a shortage of the product. It can take several years to qualify and validate a new contract manufacturer, and we cannot guarantee that we would be able to complete in a successful and timely manner the appropriate validation processes or obtain the necessary regulatory approvals for one or more additional or replacement manufacturers. Such alternate supply arrangements may not be available on commercially reasonable terms, or at all. Additionally, if we are unable to engage multiple suppliers to manufacture our products, we may have inadequate supply to meet demand for our product.

In addition, narsoplimab is a biologic drug product and any other product candidate from certain of our programs, including but not limited to MASP-2 and MASP-3, could be a biologic drug product. We do not have the internal capability to produce biologics for use in clinical trials or on a commercial scale. There are only a limited number of manufacturers of biologic drug products and we may be unable to enter into agreements on commercially reasonable terms with a sufficient number of them to meet clinical or commercial demand, if at all. The regulatory requirements for commercial supply are more stringent than for clinical supply and we cannot guarantee that a contract manufacturer producing drug product for clinical trials will be able to complete successfully the appropriate validation processes or obtain the necessary regulatory approvals for marketing approval and commercial supply in a timely manner or at all.

Our contract manufacturers may encounter difficulties with formulation, manufacturing, supply chain and/or release processes that could result in delays in clinical trials and/or regulatory submissions or that could impact adversely the commercialization of our products or product candidates, as well as in the initiation of enforcement actions by FDA and other regulatory authorities. For example, our manufacturers are required to comply with FDA’s GMP requirements and are subject to periodic inspections by FDA. If our manufacturers are unable to comply with FDA requirements, they may be unable to meet our supply needs. These difficulties also could result in the recall or withdrawal of a product from the market or a failure to have adequate supplies to meet market demand. If the safety or manufacturing quality of OMIDRIA or any product candidate supplied by contract manufacturers is compromised due to one or more of those contract manufacturers’ failure to adhere to applicable laws or for other reasons, we may not be able to maintain regulatory approval of OMIDRIA, to continue sales and marketing of OMIDRIA, to run clinical trials or to obtain and maintain regulatory approval for one or more of our product candidates, which would harm our business and prospects significantly.

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Any significant delays in the manufacture and/or supply of clinical or commercial supplies could materially harm our business, financial condition, results of operations and prospects.

Ingredients, excipients, test kits and other materials necessary to manufacture OMIDRIA or our product candidates may not be available on commercially reasonable terms, or at all, which may adversely affect the sales of OMIDRIA or development and commercialization of our product candidates.

We and our third-party manufacturers must obtain from third-party suppliers the APIs, excipients, and/or other raw materials plus primary and secondary packaging materials necessary for our contract manufacturers to produce OMIDRIA and our product candidates for our clinical trials and, to the extent approved or commercialized, for commercial distribution. Although we have entered or intend to enter into agreements with third-party suppliers that will guarantee the availability and timely delivery of APIs, excipients, test kits and materials for OMIDRIA and our product candidates, we have not yet entered into agreements for the supply of all such ingredients, excipients, test kits or materials, and we may be unable to secure all such supply agreements or guarantees on commercially reasonable terms, if at all. Even if we were able to secure such agreements or guarantees, our suppliers may be unable or choose not to provide us the ingredients, excipients, test kits or materials in a timely manner or in the quantities required. If we or our third-party manufacturers are unable to obtain the quantities of these ingredients, excipients or materials that are necessary for the manufacture of commercial supplies of OMIDRIA, our ability to generate revenue from the sale of OMIDRIA would be materially and adversely affected. Further, if we or our third-party manufacturers are unable to obtain APIs, excipients, test kits and materials as necessary for our clinical trials or for the manufacture of commercial supplies of our product candidates, if approved, potential regulatory approval or commercialization would be delayed, which would materially and adversely affect our ability to generate revenue from the sale of our product candidates.

If our clinical trials or clinical protocols are delayed, suspended or terminated, we may be unable to develop our product candidates on a timely basis, which would adversely affect our ability to obtain regulatory approvals, increase our development costs and delay or prevent commercialization of approved products.

We cannot predict whether we will encounter problems with any of our completed, ongoing or planned clinical trials or clinical data collection protocols that will cause regulatory agencies, institutional review boards or ethics committees, or us to delay our clinical trials or suspend or delay the analysis of the data from those trials. Clinical trials and clinical data protocols can be delayed for a variety of reasons, including:

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In addition, our clinical trial or development programs have been, and in the future may be, suspended or terminated by us, FDA or other regulatory authorities, or institutional review boards or ethics committees due to a number of factors, including:

If the results of our clinical trials are not available when we expect or if we encounter any delay in the analysis of data from our clinical trials, we may be unable to file for regulatory approval or conduct additional clinical trials on the schedule we currently anticipate. Many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of a product candidate. Any delays in completing our clinical trials could increase our development costs, could slow down our product development and regulatory submission process, could delay our receipt of product revenue and could make it difficult to raise additional capital. In addition, significant clinical trial delays also could allow our competitors to bring products to market before we do and impair our ability to commercialize our future products, potentially harming our business.

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Because we have a number of product candidates and development programs, we may expend our limited resources to pursue a particular product candidate or indication and fail to capitalize on product candidates or indications for which there is a greater likelihood of obtaining regulatory approval and that may be more profitable, if approved.

We have limited resources and must focus on the product candidates and clinical and preclinical development programs that we believe are the most promising. As a result, we may forgo or delay the pursuit of opportunities with other product candidates or other indications that later prove to have greater commercial potential and may not be able to progress development programs as rapidly as otherwise possible. Further, if we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product through collaboration, license or other royalty arrangements in cases in which it would have been advantageous for us to retain sole development and commercialization rights.

Our product candidates may not successfully complete clinical development or be suitable for successful commercialization or generation of revenue through partnerships, and our preclinical programs may not produce product candidates that are suitable for clinical trials.

We must successfully complete preclinical testing, which may include demonstrating efficacy and the lack of toxicity in established animal models, before commencing clinical trials for any product candidate. Many pharmaceutical and biological product candidates do not successfully complete preclinical testing. There can be no assurance that positive results from preclinical studies will be predictive of results obtained from subsequent preclinical studies or clinical trials. Even if preclinical testing is successfully completed, we cannot be certain that any product candidates that do advance into clinical trials will successfully demonstrate safety and efficacy in clinical trials. Even if we achieve positive results in early clinical trials, they may not be predictive of the results in later trials, and safety and/or efficacy outcomes of early clinical trials may not be consistent with outcomes of subsequent clinical trials. There can be no assurance that we will be able to successfully commercialize our current or future product candidates or to meet our expectations with respect to revenues or profits from such products.

We may incur substantial costs as a result of commercial disputes, claims, litigation or other legal proceedings relating to our business operations, especially with regard to patent and other intellectual property rights, and such costs or an adverse outcome in such a proceeding may adversely affect our financial condition, results of operations and/or stock price.

Our business involves numerous commercial contractual arrangements, important intellectual property rights, potential product liability, uncertainties with respect to clinical development, manufacture and regulatory approvals and other aspects that create heightened risks of disputes, claims and legal proceedings. These include claims that may be faced in one or more jurisdictions related to the safety of our product candidates and products, the development of our product candidates, our ability to obtain regulatory approval for our product candidates, our expectations regarding product development and regulatory approval, sales and marketing practices, commercial disputes including with contract manufacturers, competition, environmental matters, employment matters and other matters. These matters could consume significant time and resources, even if we are successful. Many of our competitors and contractual counterparties are significantly larger than we are and, as a result, may be able to sustain the costs of complex litigation more effectively than we can because they have substantially greater resources. In addition, we may pay damage awards or settlements or become subject to equitable remedies that could, individually or in the aggregate, have a material negative effect on our financial condition, results of operations or stock price. Any uncertainties resulting from the initiation and continuation of any litigation also could have a material adverse effect on our ability to raise the capital necessary to continue our operations.

We may initiate or become subject to litigation regarding patents and other intellectual property rights. Patent infringement litigation involves many complex technical and legal issues and its outcome is often difficult to predict and the risk involved in doing so can be substantial. Generic drug manufacturers could seek approval to market a generic version of our products or challenge our intellectual property rights with respect to our product candidates.

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It may not be feasible to detect and undertake patent enforcement action to stop infringing activity by a number of individual entities, each on a small scale, such as compounding pharmacies. Further, our industry has produced a large number of patents and it is not always clear which patents cover various types of products or methods of use. A third party may claim that we or our contract manufacturers are using inventions covered by the third party’s patent rights and may go to court to stop us from engaging in the alleged infringing activity, including making, using or selling our products and product candidates. These lawsuits are costly and could affect our results of operations and divert the attention of managerial and technical personnel. There is a risk that a court would decide that we, or our contract manufacturers, are infringing the third party’s patents and would order us or our contractors to stop the activities covered by the patents. In addition, if we or our contract manufacturers are found to have violated a third party’s patent, we or our contract manufacturers could be ordered to pay damages to the other party. We have agreed to or may agree to indemnify our contract manufacturers against certain patent infringement claims and thus may be responsible for any of their costs associated with such claims and actions. If we were sued for patent infringement, we would need to demonstrate that our products and product candidates or methods of use either do not infringe the patent claims of the relevant patent or that the patent claims are invalid, and we might be unable to do this. Proving invalidity, in particular, is difficult since it requires clear and convincing evidence to overcome the presumption of validity enjoyed by issued patents.

It is difficult and costly to protect our intellectual property and our proprietary technologies, and we may not be able to ensure their protection.

Our commercial success will depend in part on obtaining and maintaining patent protection and trade secret protection for the use, formulation and structure of our products and product candidates, the methods used to manufacture them, the related therapeutic targets and associated methods of treatment as well as on successfully defending these patents against potential third-party challenges. Our ability to protect our products and product candidates from unauthorized making, using, selling, offering to sell or importing by third parties is dependent on the extent to which we have rights under valid and enforceable patents that cover these activities.

The patent positions of pharmaceutical, biotechnology and other life sciences companies can be highly uncertain and involve complex legal and factual questions for which important legal principles remain unresolved. Changes in either the patent laws or in interpretations of patent laws in the U.S. and other countries may diminish the value of our intellectual property. Further, the determination that a patent application or patent claim meets all of the requirements for patentability is a subjective determination based on the application of law and jurisprudence. The ultimate determination by the USPTO or by a court or other trier of fact in the U.S., or corresponding foreign national patent offices or courts, on whether a claim meets all requirements of patentability cannot be assured. Although we have conducted searches for third-party publications, patents and other information that may affect the patentability of claims in our various patent applications and patents, we cannot be certain that all relevant information has been identified. Accordingly, we cannot predict the breadth of claims that may be allowed or enforced in our patents or patent applications, in our licensed patents or patent applications or in third-party patents.

We cannot provide assurances that any of our patent applications will be found to be patentable, including over our own prior art patents, or will issue as patents. Neither can we make assurances as to the scope of any claims that may issue from our pending and future patent applications nor to the outcome of any proceedings by any potential third parties that could challenge the patentability, validity or enforceability of our patents and patent applications in the U.S. or foreign jurisdictions. Any such challenge, if successful, could limit patent protection for our products and product candidates and/or materially harm our business.

The degree of future protection for our proprietary rights is uncertain because legal means afford only limited protection and may not adequately protect our rights or permit us to gain or keep our competitive advantage. In addition, to the extent that we are unable to obtain and maintain patent protection for one of our products or product candidates or in the event that such patent protection expires or is limited to method of use patent protection, it may no longer be cost-

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effective to extend our portfolio by pursuing additional development of a product or product candidate for follow-on indications.

We also may rely on trade secrets to protect our technologies or products, especially where we do not believe patent protection is appropriate or obtainable. Although we use reasonable efforts to protect our trade secrets, our employees, consultants, contractors, outside scientific collaborators and other advisers may unintentionally or willfully disclose our information to competitors. Enforcing a claim that a third-party entity illegally obtained and is using any of our trade secrets is expensive and time-consuming, and the outcome is unpredictable. In addition, courts outside the U.S. are sometimes less willing to protect trade secrets. Moreover, our competitors may independently develop equivalent knowledge, methods and know-how.

Our indebtedness and liabilities could limit the cash flow available for our operations and expose us to risks that could adversely affect our business, financial condition and results of operations.

As of December 31, 2020, we had issued $320.0 million total aggregate principal amount of our 2023 Notes and 2026 Notes, and we had approximately $1.8 million of outstanding finance lease obligations. We may incur additional indebtedness to meet future financing needs. Our existing and future indebtedness could have significant negative consequences for our security holders and our business, results of operations and financial condition by, among other things:

Our ability to make scheduled payments of the principal of, to pay interest on, or to refinance our indebtedness, including the Convertible Notes, depends on our future performance, which is subject to many factors, including, economic, financial, competitive and other circumstances beyond our control. Our business may not generate sufficient funds, and we may otherwise be unable to maintain sufficient cash reserves, to pay amounts due under our indebtedness, including the Convertible Notes, and our cash needs may increase in the future. In addition, future indebtedness that we may incur may contain, financial and other restrictive covenants that limit our ability to operate our business, raise capital or make payments under our other indebtedness. If we fail to comply with these covenants or to make payments under our indebtedness when due, then we would be in default under that indebtedness, which could, in turn, result in that and our other indebtedness becoming immediately payable in full.

Our competitors may develop products that are less expensive, safer or more effective, or which may otherwise diminish or eliminate the success of any products that we may commercialize.

We may not achieve commercial success if our competitors, many of whom have significantly more resources and experience than we, market products that are safer, more effective, less expensive or faster to reach the market than any products that we may develop and commercialize. Our competitors also may market a product that proves to be unsafe or ineffective, which may affect the market for our competing product, or future product, regardless of the safety or efficacy of our product. The failure of OMIDRIA or any future product that we may market to compete effectively with

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products marketed by our competitors would impair our ability to generate revenue, which would have a material adverse effect on our future business, our financial condition and our results of operations.

The loss of members of our management team could substantially disrupt our business operations.

Our success depends to a significant degree on the continued individual and collective contributions of our management team. The members of our management team are at-will employees, and we do not maintain any key-person life insurance policies other than on the life of Gregory A. Demopulos, M.D., our president, chief executive officer and chairman of the board of directors. Losing the services of any key member of our management team, whether from death or disability, retirement, competing offers or other causes, without having a readily available and appropriate replacement could delay the execution of our business strategy, cause us to lose a strategic partner, or otherwise materially affect our operations.

We rely on highly skilled personnel and, if we are unable to retain or motivate key personnel or hire qualified personnel, we may not be able to maintain our operations or grow effectively.

Our performance is largely dependent on the talents and efforts of highly skilled individuals, many of whom possess specialized expertise that may be difficult to replace. Our future success depends on our continuing ability to identify, hire, develop, motivate and retain highly skilled personnel for all areas of our organization. If we are unable to hire and train a sufficient number of qualified employees for any reason, we may not be able to implement our current initiatives or grow effectively. We maintain a rigorous, highly selective and time-consuming hiring process. We believe that our approach to hiring has significantly contributed to our success to date. If we do not succeed in attracting qualified personnel and retaining and motivating existing personnel, our existing operations may suffer and we may be unable to grow effectively.

We may encounter difficulties managing our growth, which could delay our business plans or adversely affect our results of operations.

To manage our future growth, we must continue to implement and improve our managerial, operational and financial systems and continue to recruit, train and retain qualified personnel. We may not be able to implement necessary business processes and systems, recruit, train and retain additional qualified personnel and otherwise manage the growth of our enterprise due to factors such as limited financial resources and competition for qualified personnel within local, national and international markets. The expansion of our operations may lead to significant costs and may divert our management and business development resources. Any inability to manage growth could delay the execution of our business plans or disrupt our operations. Additionally, our inability to manage growth effectively could cause our operating costs to grow even faster than we currently are anticipating.

Our credit facility contains restrictive covenants that may limit our operating flexibility.

In August 2019, we entered into a loan and security agreement with Silicon Valley Bank (“SVB”), under which we may borrow up to the lesser of $50.0 million and 85.0% of our eligible accounts receivable, less certain reserves. The credit facility contains restrictive covenants that limit our ability to transfer or dispose of assets, merge with other companies or consummate certain changes of control, acquire other companies, incur additional indebtedness and liens and enter into new businesses. We therefore may not be able to engage in any of the foregoing transactions unless we obtain the consent of the lender or terminate the credit facility, which may limit our operating flexibility. In addition, our credit facility is secured by all of our assets, excluding our intellectual property and development program inventories. While we had no outstanding borrowings under the credit facility and were in compliance with all covenants as of December 31, 2020, there is no guarantee that we will be able to generate sufficient cash flow or revenue to meet these financial covenants or pay the principal and interest on any future borrowings under our facility.

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Product liability claims may damage our reputation and, if insurance proves inadequate, these claims may harm our business.

We may be exposed to the risk of product liability claims that is inherent in the biopharmaceutical industry. A product liability claim may damage our reputation by raising questions about our product’s safety and efficacy and could limit our ability to sell one or more products by preventing or interfering with commercialization of our products and product candidates. In addition, product liability insurance for the biopharmaceutical industry is generally expensive to the extent it is available at all. There can be no assurance that we will be able to obtain or maintain such insurance on acceptable terms or that we will be able to secure and maintain increased coverage for OMIDRIA or any other product we bring to market. Further, our product liability insurance coverage may not provide coverage for or may be insufficient to reimburse us for any or all expenses or losses we may suffer. A successful claim against us with respect to uninsured liabilities or in excess of insurance coverage could have a material adverse effect on our business, financial condition and results of operations.

We rely on third parties to conduct portions of our preclinical research and clinical trials. If these third parties do not perform as contractually required or otherwise expected, or if we fail to adequately supervise or monitor these parties, we may not be able to obtain regulatory approval for or commercialize our product candidates.

We rely on third parties, such as CROs, medical and research institutions and clinical investigators, to conduct a portion of our preclinical research, assist us in conducting our clinical trials or to conduct third party-sponsored clinical trials of our products and product candidates. Nonetheless, we are responsible for confirming that our preclinical research and clinical trials are conducted in accordance with applicable regulations, the relevant trial protocol and within the context of approvals by an institutional review board or ethics committee, and we may not always be successful in ensuring such compliance. Our reliance on these third parties does not relieve us of responsibility for ensuring compliance with FDA and other regulations and standards for conducting, monitoring, recording and reporting the results of preclinical research and clinical trials to assure that data and reported results are credible and accurate and that the trial participants are adequately protected. If these third parties do not successfully carry out their contractual duties or regulatory obligations or meet expected deadlines, if the third parties need to be replaced or if the quality or accuracy of the data they obtain is compromised due to their failure to adhere to our clinical protocols or regulatory requirements or for other reasons, our preclinical and clinical development processes may be extended, delayed, suspended or terminated, and we may not be able to commercialize or obtain regulatory approval for our product candidates.

We may need to maintain licenses for active ingredients from third parties to develop and commercialize some of our product candidates, which could increase our development costs and delay our ability to commercialize those product candidates.

Should we decide to use APIs in any of our product candidates that are proprietary to one or more third parties, such as our PDE7 program (OMS527), we would need to maintain licenses to those active ingredients from those third parties. If we are unable to continue to access rights to these active ingredients prior to conducting preclinical toxicology studies intended to support clinical trials, we may need to develop alternate product candidates from these programs by either accessing or developing alternate active ingredients, resulting in increased development costs and delays in commercialization of these product candidates. If we are unable to maintain continued access rights to the desired active ingredients on commercially reasonable terms or develop suitable alternate active ingredients, or if we do not meet diligence or other obligations under the corresponding licenses, we may not be able to commercialize product candidates from these programs.

We use hazardous materials in our business and must comply with environmental laws and regulations, which can be expensive.

Our research operations produce hazardous waste products, which include chemicals and radioactive and biological materials. We are subject to a variety of federal, state and local regulations relating to the use, handling, storage and disposal of these materials. Although we believe that our safety procedures for handling and disposing of these materials comply with applicable legal regulations, the risk of accidental contamination or injury from these materials cannot be eliminated. We generally contract with third parties for the disposal of such substances and store our low-level

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radioactive waste at our facility until the materials are no longer considered radioactive. We may be required to incur further costs to comply with current or future environmental and safety regulations. In addition, although we carry insurance, in the event of accidental contamination or injury from these materials, we could be held liable for any damages that result and any such liability could exceed our insurance coverage and other resources.

General Risk Factors Related to our Business

Cyber-attacks or other failures in telecommunications or information technology systems could result in information theft, data corruption and significant disruption of our business operations.

We utilize information technology systems and networks to process, transmit and store electronic information in connection with our business activities. As use of digital technologies has increased, cyber incidents, including deliberate attacks and attempts to gain unauthorized access to computer systems and networks, have increased in frequency and sophistication. These threats pose a risk to the security of our systems and networks, the confidentiality and the availability and integrity of our data. There can be no assurance that we will be successful in preventing cyber-attacks or mitigating their effects. Similarly, there can be no assurance that our collaborators, CROs, third-party logistics providers, distributors and other contractors and consultants will be successful in protecting our clinical and other data that is stored on their systems. Any cyber-attack or destruction or loss of data could have a material adverse effect on our business and prospects. In addition, we may suffer reputational harm or face litigation or adverse regulatory action as a result of cyber-attacks or other data security breaches and may incur significant additional expense to implement further data protection measures.

Our stock price has been and may continue to be volatile, and the value of an investment in our common stock may decline.

During the 12-month period ended December 31, 2020, our stock traded as high as $25.46 per share and as low as $8.50 per share. The trading price of our common stock is likely to continue to be highly volatile and could be subject to wide fluctuations in response to numerous factors, many of which are beyond our control. In addition, the stock market has experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of publicly traded companies. Broad market and industry factors may seriously affect the market price of companies’ stock, including ours, regardless of actual operating performance. These fluctuations may be even more pronounced in the trading market for our stock. In addition, in the past, following periods of volatility in the overall market and the market price of a particular company’s securities, securities class action litigation has often been instituted against these companies. This litigation, if instituted against us, could result in substantial costs and a diversion of our management’s attention and resources.

If we issue additional shares of our common stock or other securities that may be convertible into, or exercisable or exchangeable for, our common stock, our existing shareholders would experience further dilution.

To the extent that we raise additional funds in the future by issuing equity securities, our shareholders would experience dilution, which may be significant and could cause the market price of our common stock to decline significantly. In addition, approximately 12.2 million shares of common stock were subject to outstanding options and warrants as of December 31, 2020 and may become eligible for sale in the public market to the extent permitted by the provisions of various vesting agreements. As of December 31, 2020, we also had approximately 4.1 million shares of common stock reserved for future issuance under our employee benefit plans that are not subject to outstanding options. Further, to the extent we issue common stock upon conversion of the Convertible Notes, such conversion would dilute the ownership interests of existing stockholders despite the expected reduction of such dilution as a result of the capped call transactions that we entered into in connection with the original issuances of the Convertible Notes. If the holders of outstanding options or warrants elect to exercise some or all of them, or if the shares subject to our employee benefit plans are issued and become eligible for sale in the public market, or we issue common stock upon conversion of the Convertible Notes, our shareholders would experience dilution and the market price of our common stock could decline.

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Anti-takeover provisions in our charter documents and under Washington law could make an acquisition of us, which may be beneficial to our shareholders, difficult and prevent attempts by our shareholders to replace or remove our current management.

Provisions in our articles of incorporation and bylaws and under Washington law may delay or prevent an acquisition of us or a change in our management. These provisions include a classified board of directors, a prohibition on shareholder actions by less than unanimous written consent, restrictions on the ability of shareholders to fill board vacancies and the ability of our board of directors to issue preferred stock without shareholder approval. In addition, because we are incorporated in Washington, we are governed by the provisions of Chapter 23B.19 of the Washington Business Corporation Act, which, among other things, restricts the ability of shareholders owning 10% or more of our outstanding voting stock from merging or combining with us. Although we believe these provisions collectively provide for an opportunity to receive higher bids by requiring potential acquirers to negotiate with our board of directors, they would apply even if an offer may be considered beneficial by some shareholders. In addition, these provisions may frustrate or prevent any attempts by our shareholders to replace or remove our current management by making it difficult for shareholders to replace members of our board of directors, which is responsible for appointing the members of our management.

We have never declared or paid dividends on our capital stock, and we do not anticipate paying dividends in the foreseeable future.

Our business requires significant funding. We currently plan to invest all available funds and future earnings, if any, in the development and growth of our business. Additionally, under the loan and security agreement with SVB, we have agreed not to pay any dividends. Therefore, we currently do not anticipate paying any cash dividends on our common stock in the foreseeable future. As a result, a rise in the market price of our common stock, which is uncertain and unpredictable, will be the sole source of potential gain for shareholders in the foreseeable future, and an investment in our common stock for dividend income should not be relied upon.

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ITEM 1B.            UNRESOLVED STAFF COMMENTS

None.

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ITEM 2.              PROPERTIES

We lease approximately 110,308 square feet for our principal office and laboratory space in the building located at 201 Elliott Avenue West, Seattle, Washington (“The Omeros Building”), which includes approximately 5,436 square feet of laboratory space that we are subleasing to third parties. The lease term for our space is through November 2027. We also have two options to extend the lease term, each by five years. The annual base rent due under the lease for our principal office and laboratory space is $6.4 million for 2020, $6.5 million for 2021 and $6.7 million for 2022 and will increase by approximately 2.3% each year thereafter. In addition, we are responsible for paying our proportionate share of the building’s utilities, taxes, insurance and maintenance as well as a property management fee.

We believe that our facilities are sufficient for our anticipated near-term needs.

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ITEM 3.              LEGAL PROCEEDINGS

From time to time, in the ordinary course of business, we may be involved in various claims, lawsuits and other proceedings. As of the date of filing of this Annual Report on Form 10-K, we were not involved in any material legal proceedings.

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ITEM 4.              MINE SAFETY DISCLOSURES

Not applicable.

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PART II

ITEM 5.              MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED SHAREHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Market Information

Our common stock is traded on The Nasdaq Global Market under the symbol “OMER.”

Holders

As of February 25, 2021, there were approximately 61,933,806 shares of our common stock outstanding, which were held by 90 holders of record.

Dividends

We have never declared or paid any cash dividends on our capital stock. We expect to retain all available funds and future earnings to fund the development and growth of our business and we do not anticipate paying any cash dividends in the foreseeable future.

Recent Sales of Unregistered Securities

We did not sell any equity securities during the fiscal year ended December 31, 2020, other than as previously disclosed in our Current Reports on Form 8-K filed with the SEC on August 14, 2020 in transactions that were not registered under the Securities Act.

Stock Performance Graph

The following graph compares the cumulative total shareholder return for our common stock (OMER), the Nasdaq Biotechnology Index (NBI) and the Nasdaq U.S. Benchmark TR Index (NQUSBT) for the period beginning December 31, 2015 and ending December 31, 2020. This graph assumes that $100 was invested on December 31, 2015 in our common stock, the Nasdaq Biotechnology Index and the Nasdaq U.S. Benchmark TR Index. It also assumes that

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any dividends were reinvested. The data shown in the following graph are not necessarily indicative of future stock price performance.

Comparison of 5 Year Cumulative Return

Assumes Initial Investment of $100

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The foregoing information shall not be deemed to be “soliciting material” or to be “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to liability under that Section. In addition, the foregoing information shall not be deemed to be incorporated by reference into any of our filings under the Exchange Act or the Securities Act, except to the extent that we specifically incorporate this information by reference.

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ITEM 6.              SELECTED CONSOLIDATED FINANCIAL DATA

The following selected consolidated financial data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements and the

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accompanying notes included elsewhere in this Annual Report on Form 10-K. Our historical results are not necessarily indicative of the results to be expected in any future period.

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ITEM 7.              MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion and analysis should be read in conjunction with the audited annual consolidated financial statements and the related notes thereto included elsewhere in this Annual Report on Form 10-K. This discussion contains forward-looking statements reflecting our current expectations that involve risks and uncertainties. Actual results may differ materially from those discussed in these forward-looking statements due to a number of factors, including those set forth in the section entitled “Risk Factors” and elsewhere in this Annual Report on Form 10-K. For further information regarding forward-looking statements, please refer to the special note regarding forward-looking statements at the beginning of this Annual Report on Form 10-K. Throughout this discussion, unless the context specifies or implies otherwise, the terms “Company,” “we,” “us” and “our” refer to Omeros Corporation and our wholly owned subsidiaries.

Overview

We are a commercial-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, complement-mediated diseases, disorders of the central nervous system, and immune-related diseases, including cancers.

Our drug product OMIDRIA® is marketed in the United States for use during cataract surgery or intraocular lens replacement for adult and pediatric patients. Our drug candidate narsoplimab is the subject of a rolling biologics license application (“BLA”) under priority review by the U.S. Food and Drug Administration (“FDA”) for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (“HSCT-TMA”). We also have multiple Phase 3 and Phase 2 clinical-stage development programs in our pipeline, which are focused on: complement-mediated disorders, including immunoglobulin A (“IgA”) nephropathy, atypical hemolytic uremic syndrome (“aHUS”), and COVID-19. We have also initiated a Phase 1 clinical program for our MASP-3 inhibitor OMS906 targeting the alternative pathway of complement and have successfully completed a Phase 1 study in our phosphodiesterase 7 (“PDE7”) program focused on addiction. In addition, we have a diverse group of preclinical programs, including GPR174, a novel target in immuno-oncology that modulates a new cancer immunity axis that we discovered. Small-molecule and antibody inhibitors of GPR174 are part of our proprietary G protein-coupled receptor (“GPCR”) platform through which we control 54 GPCR drug targets and their corresponding compounds. We also possess a proprietary-asset-enabled antibody-generating technology. We have retained control of all commercial rights for OMIDRIA and each of our product candidates and programs.

Financial Summary

We recognized net losses of $138.1 million, $84.5 million, and $126.8 million for the years ended December 31, 2020, 2019 and 2018, respectively and our OMIDRIA revenues were $73.8 million, $111.8 million, and $29.9 million

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respectively. Historically, OMIDRIA revenues were impacted by the reimbursement status for OMIDRIA under Medicare Part B, as well as the COVID-19 pandemic.

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During the period from January 1, 2018 to September 30, 2018, OMIDRIA was not reimbursed separately when used for procedures involving patients covered by Medicare Part B, and our revenues decreased significantly. After reinstatement of pass-through reimbursement for OMIDRIA in the fourth quarter of 2018, our revenues quickly returned to levels seen in prior periods during which pass-through reimbursement was available and subsequent quarter-over-quarter revenue growth approximated historical rates. Pass-through status for OMIDRIA allowed for separate reimbursement payment (i.e., outside the packaged procedural payment) to ASCs and hospitals using OMIDRIA in procedures involving patients covered by Medicare Part B.

Pass-through reimbursement for OMIDRIA under Medicare Part B expired on October 1, 2020, and consequently, our net revenues for September and the fourth quarter of 2020 were significantly reduced. In December 2020, the Centers for Medicare & Medicaid Services (“CMS”) confirmed that OMIDRIA, as an otherwise policy packaged drug following OMIDRIA’s expiration of pass-through status on October 1, 2020, qualifies for separate payment when used on Medicare Part B patients in the ambulatory surgery center (“ASC”) setting under CMS’ policy for non-opioid pain management surgical drugs. CMS made separate payment for OMIDRIA under this policy effective retroactively as of October 1, 2020. CMS’ non-opioid separate payment policy and, as a result, separate payment for OMIDRIA thereunder, like other CMS policies in the OPPS and ASC systems, can be changed by CMS through its annual rulemaking and comment process for its outpatient prospective payment and ASC payment systems. We believe that CMS will continue its separate payment policy for non-opioid pain management surgical drugs, which has been in effect since 2019, and that OMIDRIA will continue to be separately reimbursed when used in the ASC setting.

See Part 1, Item 1, “Business—Commercial Product—OMIDRIA” for additional details regarding the pass-through reimbursement status for OMIDRIA.

We expect our net losses will continue until such time as we derive sufficient revenues from sales of OMIDRIA and/or other sources, such as licensing, product sales and other revenues from our product candidates, that are sufficient to cover our operating expenses and debt service obligations.

As of December 31, 2020, we had $135.0 million in cash and cash equivalents and short-term investments available for general corporate use and $3.8 million in accounts receivable, net.

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Results of Operations

Revenue

Our revenue consists of OMIDRIA product sales to ASCs, and hospitals in the U.S. Our product sales, net are as follows:

We launched OMIDRIA in the U.S. in the second quarter of 2015 and sell OMIDRIA primarily through wholesalers which, in turn, sell to ASCs and hospitals.

In 2020, OMIDRIA revenue decreased $38.0 million, or 34%, as compared to the year ended December 31, 2019. The decrease in revenue during 2020 compared to 2019 was due to COVID-19-related reductions in the number of elective cataract procedures from mid-March 2020 through late June 2020. The additional decrease in revenue during 2020 compared to 2019 was due to a slowdown in orders from wholesalers during September and the fourth quarter following expiration of pass-through reimbursement for OMIDRIA on October 1, 2020. In December 2020, CMS confirmed that OMIDRIA qualifies for separate payment when used in the ASC setting.

In 2019, OMIDRIA revenue increased $81.9 million, or 274%, as compared to the year ended December 31, 2018. The increase in revenue in 2019 compared to 2018 was due to significantly increased demand for OMIDRIA by ASCs and hospitals following the reinstatement of pass-through reimbursement status for OMIDRIA on October 1, 2018.

During the nine-month period from January 1, 2018 to September 30, 2018, OMIDRIA was not reimbursed separately when used for procedures involving patients covered by Medicare Part B.

Given the uncertainty and local variances in the severity and response to the COVID-19 pandemic across the U.S., and whether CMS will continue its separate payment policy for non-opioid pain management surgical drugs, which has been in effect since 2019, we may experience significant fluctuations in period-over-period OMIDRIA revenues.

Gross-to-Net Deductions

We record OMIDRIA product sales net of estimated chargebacks, rebates, distribution fees and product returns. These deductions are generally referred to as gross-to-net deductions. Our total gross-to-net provisions for the years ended December 31, 2020, 2019 and 2018 were 31.2%, 27.7% and 28.1%, respectively, of gross OMIDRIA product sales.

Our gross-to-net provision and payments for the years ended December 31, 2020, 2019 and 2018 are summarized below:

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Chargebacks and Rebates

We record a provision for estimated chargebacks and rebates at the time we recognize OMIDRIA product sales revenue and reduce the accrual when payments are made or credits are granted. Our chargebacks are related to a pharmaceutical pricing agreement, a federal supply schedule agreement, a 340B prime vendor agreement, a Medicaid drug rebate agreement and an off-invoice discount to our customers. We also record a provision for our OMIDRIAssure® patient assistance and reimbursement services program and our rebates under our purchase volume-discount programs.

Distribution Fees and Product Return Allowances

We pay our wholesalers a distribution fee for services they perform for us based on the dollar value of their purchases of OMIDRIA. We record a provision for these charges as a reduction to revenue at the time of sale to the wholesaler and make payments to our wholesalers based on contractual terms.

We allow for the return of product up to 12 months past its expiration date, or for product that is damaged or not used by our customers. We record a provision for returns upon sale of OMIDRIA to our wholesaler. When a return or claim is received, we issue a credit memo to the wholesaler against its outstanding receivable to us or we reimburse the customer.

Research and Development Expenses

Our research and development expenses can be divided into three categories: direct external expenses, which include clinical research and development and preclinical research and development activities; internal, overhead and other expenses; and stock-based compensation expense. Direct external expenses consist primarily of expenses incurred pursuant to agreements with third-party manufacturing organizations prior to receiving regulatory approval for a product candidate, contract research organizations (“CROs”), clinical trial sites, collaborators, and licensors and consultants. Costs are reported in preclinical research and development until the program enters the clinic. Internal, overhead and other expenses consist of personnel costs, overhead costs such as rent, utilities and depreciation and other miscellaneous costs. We do not generally allocate our internal resources, employees and infrastructure to any individual research project because we deploy them across multiple clinical and preclinical projects that we are advancing in parallel.

The following table illustrates our expenses associated with these activities:

Clinical research and development expenses decreased by $0.5 million between 2020 and 2019 due to timing of narsoplimab drug manufacturing activities and reduced OMS527 toxicology spending. During 2020, OMS906 clinical research and development expenses were $7.2 million, and embedded within pre-clinical research and development costs

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were $3.5 million of OMS906-related expenditures. These total expenditures of $10.7 million represent an increase of $1.8 million over the prior year.

The decrease in preclinical research and development expenses in 2020 compared to 2019 is primarily due to the migration of OMS906 from preclinical to clinical research and development beginning in the third quarter of 2020.

The increases in internal, overhead and other expenses in all years presented are primarily due to additional employee-related costs and buildout of expanded laboratory facilities in 2020 to support our research and development activities.

We expect overall research and development costs to increase in 2021 as we continue our ongoing Phase 3 clinical programs for narsoplimab and manufacture commercial drug substance in anticipation of the drug’s FDA approval for the treatment of HSCT-TMA. Our accounting policy is to expense all manufacturing costs incurred until regulatory approval is obtained in either the U.S. or Europe.

At this time, we are unable to estimate with certainty the longer-term costs we will incur in the continued development of our product candidates due to the inherently unpredictable nature of our preclinical and clinical development activities as well as the potential impact of the COVID-19 pandemic. Clinical development timelines, the probability of success and development costs can differ materially as new data become available and as expectations change. Our future research and development expenses will depend, in part, on the preclinical or clinical success of each product candidate as well as ongoing assessments of each program’s commercial potential. In addition, we cannot forecast with precision which product candidates, if any, may be subject to future collaborations, when such arrangements will be secured, if at all, and to what degree such arrangements would affect our development plans and capital requirements.

We are required to expend substantial resources in the development of our product candidates due to the lengthy process of completing clinical trials and seeking regulatory approval. Any failure or delay in completing clinical trials, or in obtaining regulatory approvals, could delay our generation of product revenue and increase our research and development expenses.

Selling, General and Administrative Expenses

Our selling, general and administrative expenses are comprised primarily of salaries, benefits and stock-compensation costs for sales, marketing and other personnel who are not directly engaged in research and development. Costs also include marketing and selling expenses, professional and legal services, general corporate costs and an allocation of our occupancy costs.

The increase in selling, general and administrative expenses, excluding stock-based compensation during both years ended December 31, 2020 and 2019 was primarily due to increased pre-commercialization activities for narsoplimab for the treatment of HSCT-TMA.

We expect that our selling, general and administrative expenses in 2021 will increase from 2020, primarily due to planned U.S. commercialization activities related to narsoplimab.

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Interest Expense

Interest expense is primarily comprised of contractual interest and amortization of debt issuance and debt discount related to our 6.25% Convertible Senior Notes (the “2023 Notes”) and 5.25% Convertible Senior Notes (the “2026 Notes”) as well as interest on our finance leases. Non-cash interest expense for 2020, 2019 and 2018 was $11.6 million, $9.2 million and $5.6 million, respectively. Interest expense increased for each of these periods due to increases in total debt outstanding for each period. For more information regarding our debt and our unsecured convertible notes, see Part II, Item 8, “Note 7—Debt” and “Note 8—Unsecured Convertible Senior Notes” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

Loss on Early Extinguishment of Debt

In August and September 2020, we issued the 2026 Notes and repurchased $115.0 million of our 2023 Notes. We recorded a $13.4 million loss on early extinguishment of debt related to expensing the unamortized discount and issuance costs associated with the repurchased 2023 Notes.

In November 2018, we issued the 2023 Notes and repaid all previously outstanding loan amounts. We incurred a loss on early extinguishment of debt of $13.0 million associated with the unamortized lender facility fee, debt issuance costs, debt discount and prepayment fees in connection with the repayment.

Other Income

Other income principally includes sublease rental income and interest earned on our cash and investments. The variations between years is primarily due to $0.8 million of expenses incurred in 2020 in connection with terminating the portion of the capped call related to the 2023 Notes that we repurchased.

Income Tax Benefit