OMER US Equity☆

ITEM1A.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 Form10-K.

Risks Related to Our Products, Programs and Operations

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

Our operations have consumed substantial amounts of cash since our incorporation, As of

December 31, 2023

, we had cash, cash equivalents and short-term investments of $171.8 million. Our cash provided by operations was $74.7 million and our net loss for the year ended

December 31, 2023

was $117.8 million. We expect to continue to spend substantial amounts to:

● initiate and conduct clinical trials and manufacture clinical and registration batches for our drug candidates;

● continue our research and development in our programs;

● make principal, interest and fee payments as required under our 5.25% Convertible Senior Notes due 2026 (the “2026 Notes”); and

● commercialize and launch drug candidates for which we may receive regulatory approval.

We expect to continue to incur additional losses until such time as we generate significant revenue from the sale of commercial products or from partnerships. We are unable to predict the extent of any future losses and cannot provide assurance that we will generate sufficient revenue from commercial products in the future to fund our operations fully. If we are unable to generate sufficient revenue from 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 drug 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 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.

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Failure to obtain and maintain regulatory approval in the U.S. or in foreign jurisdictions would prevent us from commercializing and marketing our drug candidates.

The regulatory process is subject to substantial agency discretion and risks, including those described herein and elsewhere in these “Risk Factors.” In October 2021, we received a CRL from FDA regarding our BLA for narsoplimab for the treatment of TA-TMA. In the CRL, FDA expressed difficulty in estimating the treatment effect of narsoplimab in TA-TMA and asserted that additional information would be needed to support regulatory approval. We appealed FDA’s decision to issue the CRL through a formal dispute resolution process that concluded in late 2022. Although our appeal was denied, the decision identified a potential path for resubmission of the BLA based on inclusion of certain additional information and analyses. Consistent with subsequent interactions with FDA’s review division regarding resubmission of the BLA,we submitted to FDA in the fall of 2023 an analysis plan to assess already existing clinical trial data, existing data from an historical control population available from an external source, data from the narsoplimab expanded access program, and data directed to the mechanism of action of narsoplimab. We are having ongoing discussions with the agency regarding the proposed analysis plan and are currently unable to estimate when we will submit the BLA. Additionally, the requirements for resubmission of our BLA may be costly, require significant time and may not result in approval. Ultimately, we cannot guarantee that FDA will ever approve narsoplimab for the treatment of TA-TMA or any other indication.

We also intend to market outside the U.S. any of our drug candidates that are approved in the future. 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.

If any product that we develop and commercialize does not receive adequate coverage or reimbursement from governments and/or private payers our prospects for revenue and profitability would suffer.

The success of any product that we or our third-party business partners commercialize in the future will depend heavily on the pricing, availability and duration of adequate coverage or reimbursement for any such product from government, private and other third-party payers, both in the U.S. and in other countries.

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 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, including as a result of the Inflation Reduction Act, 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.

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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.

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

Our ability to meet our future capital requirements is partially dependent on certain milestone and royalty payments that we are eligible to receive based on Rayner’s sales of OMIDRIA, and, if sales of OMIDRIA are less than anticipated and/or Rayner is unable to expand sales of OMIDRIA outside the U.S., our financial condition and results of operations may be materially adversely affected, the price of our common stock may decline and we may be unable to access needed capital on favorable terms, or at all.

In February 2024, we sold to DRI an expanded interest in OMIDRIA royalties payable by Rayner. Pursuant to the Amendment with DRI, DRI is entitled to receive all royalties on U.S. net sales of OMIDRIA between January 1, 2024 and December 31, 2031. Omeros retains the right to receive all royalties payable by Rayner on any net sales of OMIDRIA outside the U.S. payable from and after January 1, 2024, as well as all royalties on global net sales of OMIDRIA payable from and after December 31, 2031. We received $115.5 million in cash upon closing of the Amendment. Additionally, we are eligible under the Amendment to receive two milestone payments of up to $27.5 million each, payable in January 2026 and January 2028, respectively, based on achievement of certain thresholds for U.S. net sales of OMIDRIA.

The royalty rate payable by Rayner on net sales of OMIDRIA is currently 30% in the United States and 15% outside the U.S. The royalty rate is subject to further reduction to 10% of U.S. net sales upon the occurrence of certain events, including during any specific period in which OMIDRIA is no longer eligible for separate payment. The availability of royalties from Rayner and/or milestone payments from DRI is dependent on Rayner’s net sales of OMIDRIA and may be of lesser magnitude than anticipated or may not become payable at all. We cannot provide assurance that royalty income from Rayner and/or milestone payments from DRI, if they become payable, will be a meaningful source of capital in the future. Sales-based royalty income and milestone payments may be affected by any number of factors, including:

● Rayner’s ability to successfully market and sell OMIDRIA in the U.S.;

● whether, and to what extent, Rayner is able to expand sales of OMIDRIA outside the U.S.;

● pricing, coverage and reimbursement policies of government and private payers such as Medicare, Medicaid, the U.S. Department of Veterans Affairs, group purchasing organizations, insurance companies, health maintenance organizations and other plan administrators;

● a lack of acceptance by physicians, patients and other members of the healthcare community;

● interruptions in the supply of OMIDRIA;

● the availability, relative price and efficacy of the product as compared to alternative treatment options or branded, compounded or generic competing products;

● an unknown safety risk; and

● changed or increased regulatory restrictions in the U.S., EU and/or other foreign territories.

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:

● the extent and magnitude of certain payments to which we may be entitled based on Rayner’s net sales of OMIDRIA may be affected by the extent of coverage and reimbursement for OMIDRIA, market acceptance of the product and Rayner’s ability to execute an effective sales strategy;

● the extent of any payments received from any collaboration agreements or development funding arrangements that we may enter into from time to time, as well as the extent of any payments that we are required to make under existing or future collaboration and license agreements, which may include sales-based royalties and milestone payments based on the achievement of development, regulatory and sales milestones and may vary significantly from quarter to quarter;

● the timing, cost and level of investment in our research and development activities as well as expenditures we may incur to acquire or develop additional technologies, drug candidates, or in preparation for potential commercialization of our drug candidates; and

● whether we are able to obtain marketing approval for any of our drug candidates, the extent and timing of revenue from sales of any such approved product and the magnitude and timing of expenses associated with the manufacturing and sale of any such approved product.

Any of these risk factors, should one or more occur, could adversely affect our results of operations and financial condition and cause the trading price of our stock to decline.

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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 drug 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 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 drug 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 drug candidates on a timely basis, if at all. As was the case with our BLA for narsoplimab in TA-TMA, with respect to which FDA issued a CRL, even after collaborating closely with FDA or regulators with corollary responsibilities in jurisdictions outside the U.S. regarding the contents of a marketing application a regulator 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 drug candidates. FDA or other regulators 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 U.S. If we are unable to comply with these requirements, if we are required to conduct additional trials or to conduct other testing of our drug 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 drug 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 cGMPs, 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 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 drug 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.

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Any reduction in reimbursement from Medicare resulting from the IRA or other legislative or policy changes or from other government programs may result in a similar reduction in payments from private payers. These healthcare reforms and the implementation of any future cost containment measures or other reforms may prevent us from being able to generate sufficient revenue, attain and/or maintain profitability or commercialize our drug candidates. We cannot be sure whether additional legislative changes will be enacted, whether existing legislation will be implemented, interpreted or enforced as anticipated or whether FDA regulations, guidance or interpretations will be changed, or what the impact of such changes on our drug candidates, if any, may be.

We have no internal capacity to manufacture commercial or clinical supplies of our drug candidates and intend to continue to rely solely on third-party manufacturers, which could significantly limit or delay our clinical trials or regulatory submissions and may negatively impact our financial conditions and results of operations. If we are unable to establish relationships with contract manufacturers that have sufficient manufacturing capacity available to meet our needs, or if the contract manufacturers that we rely on experience difficulties manufacturing and supplying our drug candidates, or fail FDA or other regulatory inspections, then our clinical trials or regulatory submissions may be significantly limited or delayed or we may have inadequate supply to meet demand for any product that we commercialize in the future.

We rely and intend to continue to rely on third-party manufacturers to produce quantities of clinical drug supplies of our drug candidates that are needed for clinical trials and to support NDAs, BLAs, or similar applications to regulatory authorities seeking marketing approval for our drug candidates, as well as to produce inventory of our drug candidates for commercial use in anticipation of marketing approval. Global demand for contract manufacturing is volatile and the available supply of contract manufacturing capacity is limited and unpredictable. 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, or that manufacturing arrangements will meet our requirements. Our contract manufacturers previously have and may in the future require us to place orders or make other financial commitments several years in advance of manufacturing commencement based on forecasts of our long-term commercial supply requirements for drug candidates that have not yet received, and may never receive, regulatory approval. We may be required to pay significant cancellation fees or other financial penalties in connection with the withdrawal or cancellation of any binding order for manufacturing that we later determine is not needed. The fees or other financial obligations that we may incur in connection with withdrawn or cancelled orders may be material and any such financial penalty would negatively impact our financial condition and results of operations.

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, OMS906 and OMS1029 are biologic drug products and other drug candidates from certain of our programs, including but not limited to MASP-2 and MASP-3, could be biologic drug products. 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.

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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 drug 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 any drug 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 to run clinical trials or to obtain and maintain regulatory approval for one or more of our drug candidates, which would harm our business and prospects significantly.

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 our drug candidates may not be available on commercially reasonable terms, or at all, which may adversely affect the development and commercialization of our drug 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 our drug 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 our drug candidates, we have not 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. 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 drug 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 drug candidates.

We may be unable to advance clinical development of narsoplimab for treatment of COVID-19 and, even if successful, we may be unable to manufacture narsoplimab in sufficient quantities.

Narsoplimab has been used to treat critically ill COVID-19 patients under our compassionate use program with highly positive results and, in an analysis of the randomized population in the narsoplimab treatment arm of I-SPY COVID-19 trial, the addition of narsoplimab to standard-of-care treatment of critically ill COVID-19 patients resulted in a mortality benefit. Notwithstanding these results, we may determine not to continue clinical development of narsoplimab for COVID-19 and/or further clinical evaluation of narsoplimab for the treatment of COVID-19 may not be feasible as a result of a number of factors, including decreasing rates of severe illness in patients with COVID-19 and the availability of alternative preventive or therapeutic agents for COVID-19. Additionally, the results of the I-SPY-COVID-19 trial may be not be viewed by regulators, government officials and others as strong evidence of narsoplimab’s efficacy in the treatment of severe COVID-19 because the narsoplimab treatment arm of the I-SPY-COVID-19 trial was terminated prior to accrual of the maximum of 125 patients on the basis of analysis in a pre-consented population in which substantial bias was detected. Also, 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 broad availability of narsoplimab for COVID-19 patients. These risks could limit our ability to develop or commercialize a therapeutic for COVID-19.

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If our clinical trials or clinical protocols are delayed, suspended or terminated, we may be unable to develop our drug 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 have been, and in the future can be, delayed for a variety of reasons, including:

● discussions with FDA, the EMA or other foreign authorities regarding the scope or design of our clinical trials or clinical data collection protocols;

● delays or the inability to obtain required approvals from institutional review boards, ethics committees or other responsible entities at clinical sites selected for participation in our clinical trials;

● delays in enrolling patients into clinical trials, collecting data from enrolled patients or collecting historical control data for any reason including disease severity, trial or data collection protocol design, study eligibility criteria, patient population size (e.g., for orphan diseases or for some pediatric indications), proximity and/or availability of clinical trial sites for prospective patients, availability of competing therapies and clinical trials, regional differences in diagnosis and treatment, perceived risks and benefits of the product or drug candidate, disruptions due to external events or conditions affecting the localities or regions in which our clinical trials are conducted, such as terrorism, political crises, natural disasters, war and wartime conditions, such as those in Ukraine, which has affected the operation of our clinical trials of OMS906, or outbreaks of contagious disease such as the COVID-19 pandemic, which previously slowed enrollment in our clinical trials of narsoplimab;

● lower than anticipated retention rates of patients in clinical trials;

● the need to repeat or conduct additional clinical trials as a result of inconclusive or negative results, failure to replicate positive early clinical data in subsequent clinical trials, failure to deliver an efficacious dose of a drug candidate, poorly executed testing, a failure of a clinical site to adhere to the clinical protocol or to follow GCPs or other study requirements, an unacceptable study design or other problems;

● adverse findings in clinical or nonclinical studies related to the safety of our drug candidates in humans;

● an insufficient supply of drug candidate materials or other materials necessary to conduct our clinical trials;

● the need to qualify new suppliers of drug candidate materials for FDA and foreign regulatory approval;

● an unfavorable inspection or review by FDA or other regulatory authority of a clinical trial site or records of any clinical investigation;

● the occurrence of unacceptable drug-related side effects or adverse events experienced by participants in our clinical trials;

● the suspension by a regulatory agency of a trial by imposing a clinical hold; or

● the amendment of clinical trial or data collection protocols to reflect changes in regulatory requirements and guidance or other reasons as well as subsequent re-examination of amendments to clinical trial or data collection protocols by regulatory agencies, institutional review boards or ethics committees.

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In particular, because PNH and C3G, the indications for which our ongoing clinical trials are evaluating OMS906, are rare conditions, we have opened and expect to continue opening clinical sites in Ukraine and other countries that may be affected by armed conflict or political instability or that have not been traditionally established as centers for clinical research. Like Ukraine, some of these areas have been, and may continue to be, affected by such conflict, instability and/or health infrastructure challenges. Enrollment and retention of patients in, or the ability to receive results from, these clinical trials could be disrupted by the existing conditions in these areas or other geopolitical or macroeconomic developments. If patients withdraw from our trials, miss scheduled doses or follow-up visits or otherwise fail to follow trial protocols, if we are unable to resupply the drugs to clinical sites on schedule, or if our trial results are otherwise disrupted or disputed due to such conditions and developments, the integrity of data from our trials may be compromised or not accepted by FDA or other regulatory authorities, which would represent a significant setback for the development of this drug candidate.

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:

● failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols;

● inspection of the clinical trial operations or trial sites by FDA or other regulatory authorities resulting in the imposition of a clinical hold;

● our failure to comply with our regulatory obligations as a sponsor of clinical research, such as adverse event reporting, control of study drug, adequate study monitoring, and other obligations;

● the failure to remove a clinical hold in a timely manner, if at all;

● unforeseen safety issues or any determination that a trial presents unacceptable health risks;

● inability to deliver an efficacious dose of a drug candidate; or

● lack of adequate funding to continue the clinical trial or development program, including as a result of unforeseen costs due to enrollment delays, requirements to conduct additional trials and studies and/or increased expenses associated with the services of our contract research organizations (“CROs”), or other third parties.

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 drug 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.

Because we have a number of drug candidates and development programs, we may expend our limited resources to pursue a particular drug candidate or indication and fail to capitalize on drug 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 drug 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 drug 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 drug candidate, we may relinquish valuable rights to that drug 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 drug 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 drug 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 drug candidate. Many pharmaceutical and biological drug 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.

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Even if preclinical testing is successfully completed, we cannot be certain that any drug 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 drug 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 drug candidates, the development of our drug candidates, our ability to obtain regulatory approval for our drug 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. Manufacturers of generic or biosimilar drugs could seek approval to market a generic or biosimilar version of our products or challenge our intellectual property rights with respect to our drug candidates.

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 drug 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 ormay in the future 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 drug 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 drug 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 drug 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.

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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 U.S. Patent and Trademark Office 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 drug 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 drug 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-effective to extend our portfolio by pursuing additional development of a product or drug candidate for follow-on indications.

We also may rely on trade secrets to protect our technologies or drug candidates, 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, 2023, we had $213.2 million total aggregate principal amount of our 2026 Notes outstanding, and we had approximately $1.3 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:

● requiring a substantial portion of our cash flow from operations to service and repay our indebtedness, which will reduce the amount of cash available for other purposes;

● limiting our ability to obtain additional financing;

● limiting our flexibility to plan for, or react to, changes in our business;

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● diluting the interests of our existing stockholders as a result of issuing shares of our common stock upon any conversion of the Convertible Notes;

● placing us at a possible competitive disadvantage with competitors that are less leveraged than we are or have better access to capital; and

● increasing our vulnerability to adverse economic and industry conditions.

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.

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 which have significantly more resources and experience than we have, 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 future product we are developing, regardless of the safety or efficacy of our product. The failure of any future product that we may market to compete effectively with 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.

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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 exceed our forecasts.

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 drug 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 for any 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 drug 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 drug 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 drug candidates.

If we are unable to obtain licenses from third parties on commercially reasonable terms or fail to comply with our obligations under such agreements, our business could be harmed.

It may be necessary for us to use the patented or proprietary technology of third parties to commercialize our products, in which case we would be required to obtain a license from these third parties. If we are unable to license such technology, or if we are forced to license such technology on unfavorable terms, our business could be materially harmed. If we are unable to obtain a necessary license, we may be unable to develop or commercialize the affected products or product candidates, which could materially harm our business and the third parties owning such intellectual property rights could seek either an injunction prohibiting our sales, or, with respect to our sales, an obligation on our part to pay royalties and/or other forms of compensation. Even if we are able to obtain a license, it may be non-exclusive, which could enable our competitors to obtain access to the same technologies licensed to us.

If we fail to comply with our obligations under license agreements, our counterparties may have the right to terminate these agreements, in which event we might not be able to develop, manufacture or market, or may be forced to cease developing, manufacturing or marketing, any product that is covered by these agreements or may face other penalties under such agreements. Such an occurrence could materially adversely affect the value of the product or product candidate being developed under any such agreement. Termination of these agreements or reduction or elimination of our rights under these agreements may result in our having to negotiate new or reinstated agreements with less favorable terms, cause us to lose our rights under these agreements, including our rights to important intellectual property or technology, or impede, delay or prohibit the further development or commercialization of one or more product candidates that rely on such agreements.

As a non-accelerated filer, we are no longer required to comply with the auditor attestation requirements of the Sarbanes-Oxley Act.

As of December 31, 2023, we are a non-accelerated filer under the Exchange Act and, therefore, we are no longer required to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act. Therefore, our internal controls over financial reporting will not receive the level of review provided by the process relating to the auditor attestation included in annual reports of issuers that are subject to the auditor attestation requirements. In addition, we cannot predict if investors will find our common stock less attractive because we are not required to comply with the auditor attestation requirements. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and the trading price for our common stock may be negatively affected.

Our share repurchase program could affect the price of our common stock and increase volatility and may be suspended or terminated at any time, which may result in a decrease in the trading price of our common stock.

In November 2023, our board of directors authorized a share repurchase program to repurchase, from time to time, up to $50.0 million of our outstanding shares of common stock in the open market, including under trading plans established pursuant to Rule 10b5-1 and Rule 10b-18 under the Exchange Act, or in privately negotiated transactions. The share repurchase program does not have a fixed expiration date, may be suspended or discontinued at any time, and does not obligate us to acquire any amount of our common stock. The timing, manner, price, and amount of any repurchases may be determined by us at our discretion and will depend on a variety of factors, including business, economic and market conditions, prevailing stock prices, corporate and regulatory requirements, and other considerations. As of March 26, 2024, approximately $33.8 million remained available to repurchase of our outstanding shares of common stock under the share repurchase program.

Repurchases pursuant to our share repurchase program could affect our stock price and increase its volatility. The existence of a share repurchase program could also cause our stock price to be higher than it would be in the absence of such a program and could potentially reduce the market liquidity for our common stock. There can be no assurance that any repurchases will enhance shareholder value, because the market price of our common stock may decline below the levels at which we repurchased our common stock. Although our share repurchase program is intended to enhance long-term shareholder value, short-term stock price fluctuations could reduce the share repurchase program’s effectiveness.

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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. While we have not experienced any previous cybersecurity incidents that have had a material adverse effect on or company, we cannot provide assurance that a future cybersecurity incident will not occur or that it would not materially affect our business, results of operations or financial condition. 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, 2023, the closing price of our stock ranged from as high as $7.57 per share and as low as $1.08 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 15.3 million shares of common stock were subject to outstanding options as of December 31, 2023 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, 2023, we also had approximately 8.8 million additional 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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If we or the third parties upon whom we rely are adversely affected by natural disasters or other events, our business continuity and disaster recovery plans may not adequately protect us from such interruptions.

Any unplanned event, such as flood, fire, explosion, earthquake, tsunami, extreme weather condition, power shortage, power outage, telecommunication failure, or other natural or man-made accidents or incidents could disrupt our operations. If a natural disaster or other event were to occur that prevents us from using all or a significant portion of our headquarters, that damages critical infrastructure, such as the manufacturing facilities of our third-party manufacturers, or that otherwise disrupts operations, it may be difficult or, in certain cases, impossible for us to continue our business for a substantial period of time. We may not carry sufficient business interruption insurance to compensate us for all losses that may occur. The disaster recovery and business continuity plans we have in place may not be adequate in the event of a serious disaster or similar event. We may incur substantial expenses as a result of a natural disaster or other event, which could have a material adverse effect on our business, and we could potentially lose valuable data and other items. The occurrence of any of the foregoing could have a material adverse effect on our business, financial condition and results of operations.

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. 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.

ITEM1B.UNRESOLVED STAFF COMMENTS

None.

ITEM1C.CYBERSECURITY

Risk Management and Strategy

Omeros maintains a cybersecurity risk management program that is designed to assess, identify, manage and respond to risks from cybersecurity threats in a robust manner. This program shares certain common methodologies, reporting channels and governance processes applicable to our management of other risk areas, such as legal, compliance, strategic, operational and financial risk.

We utilize a range of internal and external resources to assess and identify cybersecurity threats and vulnerabilities. We access and utilize information drawn from a range of publications, reports and services to assess our cybersecurity risk profile, develop awareness of emerging cybersecurity threats and threat actors and identify risk factors that are particularly relevant to the biotechnology and pharmaceutical sector and to our company. We also work with third parties that assist us to identify, assess and manage cybersecurity risks, including external auditors, consulting firms, managed security service providers and penetration testing firms.

We have implemented and maintain various technical, physical and organizational measures, processes, standards and/or policies designed to manage and mitigate material risks from cybersecurity threats. These include data encryption, network security controls, access controls, physical security, asset management, system hardening, vulnerability management and patching and continuous monitoring of information technology systems and network telemetry data using a variety of manual and automated tools and systems designed to detect and respond to suspicious or unusual activity. We maintain systems and plans for business continuity and disaster recovery and have implemented tools and procedures for cybersecurity incident detection and response. We also operate a cybersecurity training program for employees that includes required webinars and deployment of simulated phishing and similar attacks in which threat actors utilize social engineering to gain access to company systems.

We take a risk-weighted approach to mitigation of cybersecurity risks associated with use of third-party service providers. Based on an assessment of the cybersecurity risks presented by a given third-party service provider, we seek to minimize third-party cybersecurity risk on a case-by-case basis, generally through a combination of due diligence in the selection of qualified vendors and the imposition of contractual terms requiring the vendor to maintain specified cybersecurity safeguards and/or to accept financial responsibility for security breaches occurring within the vendor’s area of responsibility.

We are not aware of any specific risks from specific cybersecurity threats, and have not experienced any previous cybersecurity incidents, that have materially affected or are reasonably likely to materially affect our company, including our business strategy, results of operations or financial condition. While we continue to invest in the security and resiliency of our information technology systems and to enhance our cybersecurity controls and processes, we cannot provide assurance that a future cybersecurity incident will not occur or that it would not materially affect our company. Please see Item 1A of Part I of this Annual Report under the heading “Risk Factors” for additional discussion about risks related to cybersecurity.

Governance

Cybersecurity is an important part of our risk management processes and an area of focus for our board of directors and management. Pursuant to its charter, the audit committee of our board of directors is responsible for the oversight of management’s efforts to address cybersecurity risk. Management reports to the audit committee on cybersecurity risk matters periodically, typically twice annually. These reports normally address matters such as: the evolving cybersecurity risk environment and the emergence of new threats; outcomes and learnings from penetration testing, security audits or vulnerability assessments; evaluation of existing controls, tools and procedures and progress on implementation of any new initiatives to manage and mitigate cybersecurity risk. In addition, members of our board of directors regularly engage in discussions with management on cybersecurity-related news events and discuss any updates to our cybersecurity risk management and strategy programs.

Our cybersecurity risk management program is managed by our Director of Information Technology (the “IT Director”), whose team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture and processes. The IT Director has been with the organization since 2007, has a post-graduate degree in Information Security, and is a member of InfraGard, a partnership between the Federal Bureau of Investigation and members of the private sector for the protection of U.S. critical infrastructure. The IT Director is informed about and monitors prevention, detection, mitigation and remediation of cybersecurity risks and incidents through various means, which may include, among other things, briefings with dedicated internal security personnel, threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us, and alerts and reports produced by security tools deployed in our information technology environment. The IT Director provides periodic reports on cybersecurity risk to the audit committee of our board of directors, as well as our chief executive officer and other members of our senior management as appropriate.

ITEM2.PROPERTIES

We lease approximately 113,060 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 7,245 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 $7.0 million for 2024, $7.1 million for 2025, $6.9 million for 2026, and $5.9 million for 2027. 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.

ITEM3.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.

ITEM4.MINE SAFETY DISCLOSURES

Not applicable.

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PARTII

ITEM5.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 March 28, 2024, there were approximately 57,942,695 shares of our common stock outstanding, which were held by 84 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 that were not registered under the Securities Act during the three fiscal years ended December 31, 2023.

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, 2018 and ending December 31, 2023. This graph assumes that $100 was invested on December 31, 2018 in our common stock, the Nasdaq Biotechnology Index and the Nasdaq U.S. Benchmark TR Index. It also assumes that any dividends were reinvested. The data shown in the following graph are not necessarily indicative of future stock price performance.

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Comparison of 5 Year Cumulative Return

Assumes Initial Investment of $100

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.

Issuer Purchases of Equity Securities

The following table provides information regarding our repurchases of our common stock during the quarter ended December 31, 2023:

(In thousands)

____________

ITEM 6. [RESERVED]

ITEM7.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 Form10-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 Form10-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 Form10-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.

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Overview

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

Complement Inhibitor Programs

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, lectin, and alternative. Omeros is focused on development of therapeutics to treat diseases associated with the lectin and/or alternative pathways of complement. Omeros is developing antibodies as well as small-molecule inhibitors of key enzymes known to be centrally involved in the in activation of the targeted pathway of complement.

Lectin Pathway / MASP 2

MASP-2, is a novel pro-inflammatory protein target that is the effector enzyme of the lectin pathway and is required for the function of this pathway. Omeros is developing antibodies and small-molecule inhibitors of MASP-2 as potential therapeutics for 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 damage, such as kidney or central nervous system injury. 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 lead drug candidate in our MASP-2 inhibitor program is narsoplimab (OMS721), a proprietary, patented human monoclonal antibody targeting MASP-2, the effector enzyme of the lectin pathway of complement. Clinical development of narsoplimab is currently focused primarily on TA-TMA and development efforts are also directed to COVID-19, ARDS and PASC. We are also developing OMS1029, a long-acting, next-generation antibody targeting MASP-2 and the lectin pathway which we expect will be well-suited to indications requiring long-term, chronic administration. In addition, we are advancing our orally administered small-molecule MASP-2 inhibitor through IND-enabling studies. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Complement Inhibitor Programs: MASP-2 Program – Lectin Pathway Disorders”.

Alternative Pathway / MASP-3

Our pipeline of clinical-stage complement-targeted therapeutic candidates also includes OMS906, a proprietary, patented monoclonal antibody targeting MASP-3, the key activator of the alternative pathway of complement. We believe OMS906 has the potential to treat a wide range of alternative pathway-related diseases and that its attributes favorably differentiate OMS906 from other marketed and in-development alternative pathway inhibitors. Clinical development of OMS906 is currently focused on rapidly advancing to Phase 3 clinical trials in multiple alternative pathway-related disorders, including PNH and C3G. We have multiple ongoing Phase 2 clinical trials evaluating OMS906 in these indications. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Complement Inhibitor Programs: MASP-3 Program – Alternative Pathway Disorders”.

PDE7 Inhibitor Programs

Our PDE7 inhibitor program, which we refer to as OMS527, comprises multiple PDE7 inhibitor compounds and is based on our discoveries of previously unknown links between PDE7 and any addiction or compulsive disorder, and between PDE7 and any movement disorders. In April 2023, we were awarded a grant from the National Institute on Drug Abuse, part of the National Institutes of Health, to develop our lead orally administered PDE7 inhibitor compound, for which we have successfully completed a Phase 1 study, for the treatment of cocaine use disorder (“CUD”). The grant amount, a total of $6.69 million over three years, is intended to support preclinical cocaine interaction/toxicology studies to assess safety of the therapeutic candidate in the presence of concomitant cocaine administration, as well as an in-patient, placebo-controlled clinical study evaluating the safety and effectiveness of OMS527 in adults with CUD who receive concurrent intravenous cocaine. The preclinical study is intended to provide the toxicology data necessary to support the human study of OMS527 in CUD. The toxicology study is underway and is expected to be completed in late 2024. Additionally, with investigators at Emory University, we are also evaluating OMS527 as a potential treatment for levodopa-induced dyskinesia, a common and debilitating side effect of long-term levodopa dosing in patients with Parkinson’s disease. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Other Clinical Programs: PDE7 Inhibitor Programs – OMS527”.

Pre-clinical Programs

We are advancing preclinical research on potential molecular and cellular therapies for cancer. On the molecular front, we have developed novel biologic platforms to target cancer cells specifically and kill them directly or indirectly through the potentiation of the immune system. Our novel molecules combine tumor antigens with a potent adjuvant and show high levels of killing in cancer cells. We believe that some of these molecules could function as therapeutic vaccines against a broad range of tumors, potentially transforming treatment of both solid tumors and hematologic cancers. On the cellular front, we are evaluating novel approaches for both adoptive T cell and CAR T therapies. We have identified specific T cell signaling pathways, which, once inhibited, significantly and preferentially enhance the expansion of memory T cells that distinctively recognize and efficiently kill tumor cells. We continue to develop and validate our novel approach, which we believe could improve response rates for patients receiving either engineered or native T cell therapies for liquid or solid tumors.

OMIDRIA Sale and Royalty Monetization Transactions

We previously developed and commercialized OMIDRIA® (phenylephrine and ketorolac intraocular solutions) 1%/0.3%, which is approved by FDA for use during cataract surgery or intraocular ("IOL") replacement to maintain pupil size by preventing intraoperative miosis (pupil constriction) and to reduce postoperative ocular pain. We marketed OMIDRIA in the U.S. from the time of its commercial launch in 2015 until December 2021.

On December 23, 2021, we sold our commercial product OMIDRIA and certain related assets, including inventory and prepaid expenses, to Rayner. Rayner paid us $126.0 million in cash at the closing and we retained all outstanding accounts receivable, accounts payable, and accrued expenses as of the closing date.

Under the Asset Purchase Agreement, we were entitled to receive a $200.0 million Milestone Payment within 30 days following an event (the "Milestone Event") that establishes separate payment for OMIDRIA for a continuous period of at least four years when furnished in the ambulatory surgery center ("ASC") setting. The Milestone Event occurred in December 2022 and we recorded a $200.0 milestone receivable. We received the Milestone Payment together with accrued interest in February 2023.

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Under the Asset Purchase Agreement, the occurrence of the Milestone Event in December 2022 triggered a reduction in the U.S. royalty rate from 50% to 30% on OMIDRIA net sales until the expiration or termination of the last issued and unexpired U.S. patent, which we expect to occur no earlier than 2035. Upon the occurrence of certain events described in the Asset Purchase Agreement, including during any specific period in which OMIDRIA is no longer eligible for certain separate payment (i.e., becomes included in the packaged payment rate for the surgical procedure) under Medicare Part B, the U.S. base royalty rate would be reduced to 10%. Pursuant to legislation enacted in late 2022, we expect separate payment for OMIDRIA under Medicare Part B to extend until at least January 1, 2028.

As a result of the OMIDRIA divestiture, the results of OMIDRIA operations have been reclassified to net income from discontinued operations, net of tax in our consolidated statements of operations and comprehensive income (loss) and excluded from continuing operations for all periods presented.

On September 30, 2022, we sold to DRI an interest in a portion of our future OMIDRIA royalty receipts and received $125.0 million in cash consideration which we recorded as an OMIDRIA royalty obligation on our consolidated balance sheet. Interest expense is recorded as a component of continuing operations. The aggregate amount of royalties to which DRI is entitled under this arrangement is capped at $188.4 million.

On February 1, 2024, we sold to DRI an expanded interest in the OMIDRIA royalties pursuant to the terms of an amended and restated royalty purchase agreement dated February 1, 2024 (the “Amendment”). We received $115.5 million in cash upon closing of the Amendment. The Amendment eliminated the caps on royalty payments effective beginning in the first quarter of 2024, and provides that DRI will now receive all royalties on U.S. net sales of OMIDRIA payable between January 1, 2024 and December 31, 2031. DRI is entitled to payment only to the extent of royalty payments that are payable on U.S. net sales of OMIDRIA on or before December 31, 2031 and DRI has no recourse to our assets other than its interest in the OMIDRIA royalties. Omeros retains the right to receive all royalties payable by Rayner on any net sales of OMIDRIA outside the U.S. payable from and after January 1, 2024, as well as all royalties on global net sales of OMIDRIA payable from and after December 31, 2031. In addition to the cash consideration received at closing, the Amendment also entitles us to receive a milestone payment ranging between $10.0 million and $27.5 million if U.S. net sales of OMIDRIA reach applicable thresholds ranging between a total of $156.0 million and $160.0 million for any period of four consecutive quarters ending prior to January 1, 2026 as well as a separate milestone payment ranging between $8.0 million and $27.5 million if U.S. net sales of OMIDRIA reach applicable thresholds ranging between a total of $181.0 million and $185.0 million for any period of four consecutive quarters ending prior to January 1, 2028. See Part II, Item 8, “Note 8 – OMIDRIA Royalty Obligation” to our Consolidated Financial Statements in this Annual Report on Form 10-K for additional information.

As of December 31, 2023, we had cash, cash equivalents and short-term investments of $171.8 million and, in February 2024, we received $115.5 million from DRI.

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Results of Operations

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 drug candidate, CROs, clinical trial sites, collaborators, licensors and consultants. Pre-clinical research and development includes costs prior to beginning Phase 1 studies in human subjects. Internal, overhead and other expenses primarily consist of costs for personnel, overhead, rent, utilities and depreciation. The discontinued operations of OMIDRIA relates to the costs of drug manufacturing stability, quality control testing and costs of employees and consultants. The following table illustrates our expenses associated with these activities:

Year Ended

Year Ended December 31,

(In thousands)

Continuing research and development expenses:

Direct external expenses:

Clinical research and development:

Discontinued research and development expenses — — 3,839

Clinical research and development expenses increased $4.8 million between 2023 and 2022. The $16.5 million increase in OMS906 development costs was due to an increase in manufacturing and Phase 2 clinical trial costs and a $5.0 million development milestone paid in 2023 under a technology license agreement. The $3.6 million increase in OMS1029 expense wasprimarily due to costs associated with initiation of human trials and other clinical development costs, i.e. the transition from preclinical to clinical development status in the third quarter of 2022. These increases were offset by decreased narsoplimab manufacturing costs during 2023.

The $3.5 million increase in clinical research and development costs between 2022 and 2021 was primarily due to the advancement of OMS1029 from preclinical status to clinical research and development status on initiation of the Phase 1 clinical trial in the third quarter of 2022. Additionally, we incurred increased narsoplimab drug manufacturing costs in 2022 compared to the prior year. These costs were partially offset by reduced costs in our OMS906 program resulting from the completion of toxicology study work in the second quarter of 2022.

Preclinical research and development expenses decreased $2.1 million in 2023 compared to 2022, primarily due to the migration of OMS1029 from preclinical to clinical research and development status during the third quarter of 2022, offset by an increase in preclinical oncology research costs during 2023.The $7.8 million decrease in 2022 over 2021 in preclinical research and development expenses was primarily due to the migration of OMS1029 from preclinical to clinical research and development status during the third quarter of 2022.

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The changes in stock-based compensation expense between the three covered years were due to the valuations of employee stock options.

We expect our overall research and development costs in 2024 to be similar to 2023, driven by commercial narsoplimab manufacturing costs expected to be incurred prior to FDA approval of TA-TMA, increases inOMS906 clinical and manufacturing costs, and decreases in OMS721 clinical costs. Our accounting policy is to expense all manufacturing costs related to drug candidates until regulatory approval is reasonably assured 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 drug candidates due to the inherently unpredictable nature of our preclinical and clinical development activities. 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 drug candidate as well as ongoing assessments of each program’s commercial potential. In addition, we cannot forecast with precision which drug 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 drug 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-based compensation costs for sales, marketing and administrative 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.

Year Ended December 31,

(In thousands)

Continuing selling, general and administrative expenses:

Discontinued selling, general and administrative expenses — — 25,428

Total selling, general and administrative expenses $ 49,660 $ 50,668 $ 80,270

Continuing selling, general and administrative expenses, excluding stock-based compensation expense, decreased $4.1 million between 2022 and 2021 primarily related to reduced spending on pre-commercialization sales and marketing activities which were higher in 2021 as we prepared for the then anticipated approval and commercial launch of narsoplimab for the treatment of TA-TMA.

The changes in stock-based compensation expense between the three covered years were due to the valuations of employee stock options.

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Our selling, general and administrative expenses for 2024 will be highly dependent on whether narsoplimab receives U.S. marketing approval for treatment of TA-TMA. If TA-TMA is approved in 2024, we expect to hire a field sales force and initiate commercial launch activities which will increase our selling, general and administrative expenses. If narsoplimab is not approved in 2024, our selling, general and administrative expenses are expected to decrease in 2024.

Interest Expense

Year Ended December 31,

(In thousands)

Interest expense is primarily comprised of interest and amortization of debt discount and issuance costs related to our convertible senior notes and interest on our DRI royalty obligation (see Part II, Item 8, "Note 6 – Convertible Senior Notes" and "Note 8 – OMIDRIA Royalty Obligation” to our Consolidated Financial Statements in this Annual Report on Form 10-K for additional information).

Interest expense increased $8.1 million in 2023 compared to 2022 primarily due to incurring interest from our DRI royalty obligation for the full year. Interest expense increased $3.0 million in 2022 compared to 2021 primarily due to interest incurred from our DRI royalty obligation only in the fourth quarter of 2022.

Interest and Other Income

Year Ended December 31,

(In thousands)

The $12.3 million increase in interest and other income between 2023 and 2022 was primarily due to holding higher average cash and investment balances than in the prior year as a result of receiving a $200.0 million Milestone Payment from Rayner in February 2023. The $2.3 million increase in interest and other income between 2022 and 2021 was primarily attributable to obtaining significantly higher interest rates on our cash and investments in 2022.

We expect interest and other income in 2024 to be less than 2023 primarily due to lower average cash and investment balances during 2024.

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Gain on Early Extinguishment of Convertible Senior Notes

Year Ended December 31,

(In thousands)

Gain on early extinguishment of convertible senior notes $ 4,112 $ — $ —

In December 2023, we repurchased $9.1 million par value of our 2026 Notes at a discount, realizing a $4.1 million non-cash gain on extinguishment.

Net Income from Discontinued Operations, Net of Tax

On December 23, 2021, we sold our commercial drug, OMIDRIA, to Rayner. As a result of the OMIDRIA divestiture, the results of OMIDRIA operations have been reclassified to discontinued operations for all periods presented.

Net income from OMIDRIA discontinued operations, net of tax is shown below:

Year Ended December 31,

(In thousands)

Product sales, net $ — $ — $ 110,735

Costs and expenses — — 30,631

Gain on sale of OMIDRIA — — 305,648

Interest on OMIDRIA contract royalty asset 15,315 18,634 —

(1) For further discussion of income tax expense, please refer to Part II, Item 8, “Note 13 – Income Taxes” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

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Gain on the Sale of OMIDRIA

On December 23, 2021, we completed the sale of OMIDRIA to Rayner and received $126.0 million in cash at the closing. Additionally, we recorded an OMIDRIA contract royalty asset of $184.6 million for the rights to receive future royalties from Rayner on OMIDRIA net sales. The sale of OMIDRIA qualified as an asset sale under GAAP.

Rayner’s U.S. net sales of OMIDRIA for the years ended December 31, 2023 and 2022 were $135.3 million and $130.9 million, respectively. We earned royalties of $40.6 million and $65.4 million on OMIDRIA net sales for the years ended December 31, 2023 and 2022, respectively, which we recorded as a reduction from the OMIDRIA contract royalty asset. The decrease in royalty earnings between the years ended December 31, 2023 and 2022 was due to a reduction of our royalty rate on U.S. net sales of OMIDRIA from 50% to 30% upon achievement of the $200.0 million Milestone Event. (For further discussion of discontinued operations, please refer to Part II, Item 8, “Note 7 – Discontinued Operations – Sale of OMIDRIA” to our Consolidated Financial Statements in this Annual Report on Form 10-K).

Milestone Income

The Milestone Event occurred in December 2022, entitling us to receive a Milestone Payment of $200.0 million from Rayner. We received the Milestone Payment together with accrued interest in February 2023.

Interest Income

During the years ended December 31, 2023 and 2022, we recorded $15.3 million and $18.6 million, respectively, of income in discontinued operations, representing interest income on the outstanding OMIDRIA contract royalty asset at an implied interest rate of 11.0%.

Remeasurement Adjustments

During the years ended December 31, 2023 and 2022, we recorded $41.2 million and $14.5 million, respectively, of remeasurement adjustments. The $26.7 million increase in 2023 was primarily attributable to assigning a greater probability of achieving higher royalty earnings on net sales of OMIDRIA as supported by our most recent transaction with DRI, which closed on February 1, 2024.

Income Tax Expense

For the years ended December 31, 2023, 2022 and 2021, we recorded state income tax expense of $0.5 million, $4.0 million and $1.0 million, respectively, which could not be offset by prior period net operating losses and tax credit carryforwards.

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Financial Condition- Liquidity and Capital Resources

As of December 31, 2023, we had cash, cash equivalents and short-term investments of $171.8 million.For the year ended December 31, 2023, our cash provided by operations was $74.7 million and our net loss was $117.8 million. In February 2024, we received $115.5 million upon the sale to DRI of our U.S. OMIDRIA royalty receipts payable between January 1, 2024 and December 31, 2031.

Historically, we have incurred net losses from continuing operations and negative operating cash flows. We have not yet established an ongoing source of revenue sufficient to cover our operating costs; therefore, we potentially need to continue to raise additional capital to accomplish our business plan and to retire our outstanding convertible senior notes due in 2026. We plan to continue to fund our operations for at least the next twelve months with our existing cash and investments and the $115.5 million we received in February 2024 from DRI. We have a sales agreement to sell shares of our common stock, from time to time, in an “at the market” equity offering facility through which we may offer and sell shares of our common stock equaling an aggregate amount up to $150.0 million. Should it be determined to be strategically advantageous, we could pursue debt financings as well as public and private offerings of our equity securities, similar to those we have previously completed, or other strategic transactions, which may include licensing a portion of our existing technology. Should it be necessary to manage our operating expenses, we could also reduce our projected cash requirements by delaying clinical trials, reducing selected research and development efforts, or implementing other restructuring activities.

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Cash Flow Data

Year Ended December 31,

(In thousands)

Selected cash flow data

Cash provided by (used in):

Operating Activities.Net cash provided by operating activities for the year ended December 31, 2023 increased by $161.2 million compared to the same period in 2022. This increase was primarily due to collecting the $200.00 million Milestone Payment from Rayner in the current year and a $15.3 increase in accounts payable and accrued expenses. These increases were offset by a $26.7 million change in the remeasurement of the OMIDRIA contract royalty asset, $8.7 million related to the accretion of interest on U.S. government treasury bills and a $4.1 million gain on the early extinguishment of a portion of our 2026 Notes.

Net cash used in operating activities for the year ended December 31, 2022 decreased by $23.2 million compared to the same period in 2021. This change was primarily due to a decrease in net income of $146.8 million as we recognized $310.6 million of non-cash gain from the sale of OMIDRIA in the prior year and a change in cash collections of $124.7 million through accounts receivables and royalty earnings. This was offset by a $200.0 million milestone receivable recognized in 2022 as well as $35.6 million in non-cash charges and $29.7 million of accounts payable, accrued expenses and other.

Investing Activities.Net cash provided by investing activities increased $155.0 million during 2023 compared to 2022 driven by net proceeds from the purchase and sale of investments.

Net cash provided by investing activities decreased $321.3 million during 2022 compared to 2021. This was driven by a $194.5 million decrease in net proceeds from the purchase and sale of investments and recognizing $126.0 million in proceeds from the sale of OMIDRIA in 2021.

Financing Activities.Net cash used in financing activities decreased $230.3 million during 2023 compared to the prior year. The decrease was primarily due to receiving $125.0 million in 2022 in connection with selling a portion of our OMIDRIA royalties to DRI and extinguishing $95.0 million of our 6.25% convertible senior notes (the "2023 Notes"). In addition, we paid $4.9 million to retire $9.1 million par value of our 2026 Notes and repurchased $4.7 million of our common stock through a stock repurchase program in 2023.

Net cash provided by financing activities increased $117.9 million during 2022 compared to the prior year. The increase was primarily due to receiving cash proceeds of $125.0 million in connection with the sale of a portion of our OMIDRIA royalties to DRI, which was partially offset by a reduction in stock option exercises of $8.0 million during 2022.

Contractual Obligations and Commitments

Operating Leases

We lease our office and laboratory space in The Omeros Building under a lease agreement with BMR - 201 Elliott Avenue LLC. The initial term of the lease ends in November 2027 and we have two options to extend the lease term, each by five years. As of December 31, 2023, the remaining aggregate non-cancelable rent payable under the initial term of the lease, excluding common area maintenance and related operating expenses, was $26.9 million.

We have finance leases for certain laboratory and office equipment that have lease terms expiring through November 2026.

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Convertible Notes

For more information regarding the convertible senior notes extinguished in mid-November 2023 and convertible senior notes due in February 2026, see Part II, Item 8, “Note 6 - Convertible Senior Notes”.

OMIDRIA Royalty Obligation

For more information regarding the OMIDRIA Royalty Obligation, see Part II, Item 8, “Note 8 - OMIDRIA Royalty Obligation”.

Goods& Services

We have certain non-cancelable obligations under other agreements for the acquisitions of goods and services associated with the manufacturing of our drug candidates, which contain firm commitments. As of December 31, 2023, our aggregate firm commitments were $25.8 million.

We may be required, in connection with in-licensing or asset acquisition agreements, to make certain royalty and milestone payments and we cannot, at this time, determine when or if the related milestones will be achieved or whether the events triggering the commencement of payment obligations will occur. Therefore, such payments are not included in the table above. For information regarding agreements that include these royalty and milestone payment obligations, see Part II, Item 8, “Note 10 - Commitments and Contingencies” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

Critical Accounting Policies and Significant Judgments and Estimates

The preparation of our consolidated financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances; however, actual results could differ from those estimates. An accounting policy is considered critical if it is important to a company’s financial condition and results of operations and if it requires the exercise of significant judgment and the use of estimates on the part of management in its application. Although we believe that our judgments and estimates are appropriate, actual results may differ materially from our estimates. For a summary of our critical accounting policies, see Part II, Item 8, “Note 2 - Significant Accounting Policies” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

We believe the following to be our critical accounting policies because they are both important to the portrayal of our financial condition and results of operations and they require critical judgment by management and estimates about matters that are uncertain:

● revenue recognition;

● OMIDRIA royalties and contract asset accounting;

● OMIDRIA royalty obligation accounting;

● research and development expenses related to clinical trials;

● accounting for convertible debt issuances, primarily related to fair valuing debt and issuance costs; and

● stock-based compensation, primarily related to our fair value assumptions.

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If actual results or events differ materially from those contemplated by us in making these estimates, our reported financial condition and results of operations for future periods could be materially affected.

Product Revenue Recognition

Prior to the December 23, 2021 sale of OMIDRIA to Rayner, we recorded revenue from product sales when the product was delivered to our wholesalers and title for the product was transferred. Product sales were recorded net of wholesaler distribution fees and estimated chargebacks, rebates, returns and purchase-volume discounts. Accruals or allowances were established for these deductions in the same period when revenue was recognized, and actual amounts incurred were offset against the applicable accruals or allowances. We reflected each of these accruals or allowances as either a reduction in the related accounts receivable or as an accrued liability depending on how the amount was expected to be settled.

OMIDRIA Royalties, Milestones and Contract Royalty Assets

We have rights to receive future royalties from Rayner on OMIDRIA net sales at royalty rates that vary based on geography and certain regulatory contingencies. Therefore, future OMIDRIA royalties are treated as variable consideration. To measure the OMIDRIA contract royalty asset, we used the expected value approach which is the discounted sum of probability-weighted royalty payments, we would receive using a range of potential outcomes, to the extent that it is probable that a significant reversal in the amount of cumulative income recognized will not occur. Our calculations take the net present value of the sum to arrive at the OMIDRIA contract royalty asset stated on the balance sheet. We revalued the contract royalty asset to reduce the applicable royalty percentage from 50% to 30%, as required under the Asset Purchase Agreement following the occurrence of the December 2022 event triggering the $200.0 million Milestone Payment. Royalties earned will be recorded as a reduction to the OMIDRIA contract royalty asset. The amount recorded in discontinued operations in future periods will reflect interest earned on the outstanding OMIDRIA contract royalty asset and any amounts received different from the expected royalties recorded at closing. The OMIDRIA contract royalty asset is subject to changes in net sales of OMIDRIA. All else being equal, a 10% decrease or increase in net sales results in a $16.8 million change in value of the OMIDRIA contract royalty asset, resulting in a potential contract royalty asset valued within the range of $151.3 million to $184.9 million. Changes in net sales could occur due to various risks such as competitors entering the market, changes in the standard of care for cataract patients and loss of separate payment status for OMIDRIA. In determining the value of the OMIDRIA contract royalty asset, we have considered all of these factors. The OMIDRIA contract royalty asset will be re-measured periodically using the expected value approach based on actual results and future expectations. Any required adjustment to the OMIDRIA contract royalty asset will be recorded in discontinued operations.

We receive monthly royalty payments based on Rayner’s OMIDRIA product sales in accordance with the Asset Purchase Agreement. Upon the closing of the Asset Purchase Agreement, we determined the expected minimum net present value of future OMIDRIA royalty receipts and recognized the amount as a gain on the sale of OMIDRIA in discontinued operations on our income statement and as an OMIDRIA contract royalty asset on our balance sheet. To determine the OMIDRIA contract royalty asset, we used the expected value approach which is based on the sum of probability-weighted payments we would receive using a range of potential outcomes at an effective interest rate of 11%. The contract royalty asset excludes any revenue which potentially may be reversed in the event of an over estimation.

OMIDRIA Royalty Obligations

The sale of any portion of our OMIDRIA royalty receipts is treated as a liability on our consolidated balance sheet to the extent that any of our royalties are capped, as this does not result in the transfer of a participating interest. We amortize royalty obligation liabilities over the term of the arrangement using the effective interest method and classify interest expense as a component of continuing operations.

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To the extent our estimates of future royalties are less than previous estimates, we will adjust the carrying amount of the royalty obligation to the present value of the revised estimated cash flows, discounted at the original effective interest rate utilizing the cumulative catch-up method. The adjustment would be recognized as a component of net income (loss) from continuing operations.

Research and Development Expenses

Research and development costs are comprised primarily of:

● contracted research and manufacturing costs;

● clinical study costs;

● costs of personnel, including salaries, benefits and stock compensation;

● consulting arrangements;

● depreciation and an allocation of our occupancy costs; and

● other expenses incurred to sustain our overall research and development programs.

Contracted research and manufacturing costs are primarily incurred in the development and production of our drug candidates. Prior to approval, our estimates are based on the timing of services provided. We record accrued expenses equal to our estimated expense in excess of amount invoiced by the suppliers.

Clinical trial expenses are estimated on a cost per patient that varies depending on the clinical trial site. As actual costs become known to us, we adjust our estimates; these changes in estimates may result in understated or overstated expenses at any given point in time.

Convertible Debt Issuances

On January 1, 2021, we adopted Accounting Standards Update (“ASU”) 2020-06, Debt—Debt with Conversion Options (Subtopic 470.20 and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) on a modified retrospective basis. ASU 2020-06 removes the separate liability and equity accounting for our convertible senior notes. As of January 1, 2021, we account for our convertible senior notes wholly as debt. Prior to January 1, 2021, we accounted for convertible debt that may be settled wholly or partially in cash upon conversion as having both a liability component (debt) and an equity component (conversion option). The cash conversion guidance applies as the embedded conversion features meet the requirements for a derivative scope exception for instruments that are both indexed to an entity’s own stock and classified in stockholders’ equity in the balance sheet. Principal cash proceeds from the instrument are allocated first to the liability component based on the fair value of non-convertible debt using the income and market-based approaches to determine an effective interest rate for present valuing the cash proceeds. For the income-based approach, we use a convertible bond pricing model that includes several assumptions such as volatility and a risk-free rate. For the market-based approach, we observe the price of derivative price instruments purchased in conjunction with our convertible senior note issuances or evaluate issuances of convertible debt securities by other companies with similar credit risk ratings at the time of issuance. The amount of the equity component is then calculated by deducting the fair value of the liability component from the principal amount of the instrument. Issuance costs from the instrument are then allocated to the liability and equity components in the same proportion as the proceeds. The equity component of the cash principal proceeds and the liability component of the issuance costs represent a debt discount.

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Transactions involving contemporaneous exchanges of cash between the same debtor and creditor in connection with the issuance of a new debt obligation and satisfaction of an existing debt obligation by the debtor are evaluated as a modification or an exchange transaction depending on whether the exchange is determined to have substantially different terms. We extinguished the 2023 Notes at maturity. The partial repurchase of the 2026 Notes was deemed to be a modification which we accounted for as a debt extinguishment.

Stock-Based Compensation

Stock-based compensation expense is recognized for all share-based payments made to employees, directors and non-employees based on estimated fair values. The fair value of our stock options is calculated using the Black-Scholes valuation model, which requires assumptions regarding volatility, risk-free rates, forfeiture rates and expected option life. We estimate forfeitures for expense recognition based on our historical experience. Groups of employees that have similar historical forfeiture behavior are considered separately. If any of the assumptions used in the Black-Scholes model change significantly, stock-based compensation expense for new awards may differ materially from that recorded for existing awards and stock-based compensation for non-employees will vary as the awards are re-measured over the vesting term.

Recent Accounting Pronouncements

Please refer to Part II, Item 8, “Note 2 - Significant Accounting Policies” to our Consolidated Financial Statements in this Annual Report on Form 10-K for information regarding recent accounting pronouncements.

ITEM7A.QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Our exposure to market risk is primarily confined to our investment securities. The primary objective of our investment activities is to preserve our capital to fund operations, and we do not enter into financial instruments for trading or speculative purposes. We also seek to maximize income from our investments without assuming significant risk. To achieve our objectives, we maintain a portfolio of investments in high-credit-quality securities. As of December 31, 2023, we had cash, cash equivalents and short-term investments of $171.8 million. In accordance with our investment policy, we invest funds in highly liquid, investment-grade securities. The securities in our investment portfolio are not leveraged and are classified as held-to-maturity. We currently do not hedge interest rate exposure. Because of the short-term maturities of our investments, we do not believe that an increase in market rates would have a material negative effect on the realized value of our investment portfolio. We actively monitor changes in interest rates and, with our current portfolio of short-term investments which we intend to hold to maturity, we are not exposed to significant loss due to changes in interest rates.

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ITEM8.FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Index to Consolidated Financial Statements

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 42) 58

Consolidated Balance Sheets 60

Consolidated Statements of Operations and Comprehensive Income (Loss) 61

Consolidated Statement of Shareholders’ Equity (Deficit) 62

Consolidated Statements of Cash Flows 63

Notes to Consolidated Financial Statements 64

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Report of Independent Registered Public Accounting Firm

To the Shareholders and the Board of Directors Omeros Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Omeros Corporation (the Company) as of December 31, 2023 and 2022, the related consolidated statements of operations and comprehensive income (loss), shareholders' equity (deficit) and cash flows for each of the three years in the period ended December 31, 2023, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of an expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the account or disclosures to which it relates.

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OMIDRIA Contract Royalty Asset

/s/Ernst & Young LLP

We have served as the Company’s auditor since 1998.

Seattle, Washington

April 1, 2024

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OMEROS CORPORATION

CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share data)

December 31, December 31,

Assets

Current assets:

OMIDRIA contract royalty asset, short-term 29,373 28,797

Prepaid expense and other assets 8,581 6,300

Liabilities and shareholders’ equity (deficit)

Current liabilities:

Current portion of convertible senior notes, net — 94,381

Current portion of OMIDRIA royalty obligation 8,576 1,152

Current portion of lease liabilities 5,160 4,310

Other accrued liabilities - noncurrent 2,088 444

Commitments and contingencies (Note 10)

Shareholders’ equity (deficit):

Total shareholders’ equity (deficit) (24,983 ) 85,684

Total liabilities and shareholders’ equity (deficit) $ 378,269 $ 590,969

See accompanying Notes to Consolidated Financial Statements

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OMEROS CORPORATION

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(In thousands, except share and per share data)

Year Ended December 31,

Costs and expenses:

Gain on early extinguishment of convertible senior notes 4,112 — —

Basic and diluted net income (loss) per share:

Net loss from continuing operations $ (2.79 ) $ (2.90 ) $ (3.07 )

Net income from discontinued operations 0.91 3.66 6.19

See accompanying Notes to Consolidated Financial Statements

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OMEROS CORPORATION

CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY (DEFICIT)

(In thousands, except share data)

Additional Total

Common Stock Paid-in Accumulated Shareholders’

Shares Amount Capital Deficit Equity/(Deficit)

Issuance of common stock upon grant of restricted stock awards 11,700 — 91 — 91

At the market offering fees — — (241 ) — (241 )

Issuance of common stock upon exercise of stock options 101,160 1 414 — 415

Issuance of common stock upon exercise of stock options 36,726 — 150 — 150

See accompanying Notes to Consolidated Financial Statements

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OMEROS CORPORATION

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

Year Ended December 31,

Operating activities:

Non-cash interest expense on convertible senior notes 1,853 1,830 1,696

Remeasurement on OMIDRIA contract royalty asset (41,167 ) (14,457 ) —

Interest on OMIDRIA contract royalty asset (15,315 ) (18,634 ) —

Accretion on U.S. government treasury bills, net (8,714 ) — —

Gain on early extinguishment of convertible senior notes (4,112 ) — —

Gain on sale of OMIDRIA, gross — — (310,563 )

Non-cash interest expense on future royalty obligation — 1,695 —

Changes in operating assets and liabilities:

Investing activities:

Purchases of property and equipment (426 ) (113 ) (277 )

Cash proceeds on sale of OMIDRIA — — 125,993

Financing activities:

Payments on convertible senior notes (99,873 ) — —

Repurchases on common stock (4,654 ) — —

Principal payments on OMIDRIA royalty obligation (1,152 ) (417 ) —

Payments on finance lease obligations (555 ) (750 ) (1,823 )

Proceeds upon exercise of stock options 150 415 8,383

Proceeds upon entering into OMIDRIA royalty obligation — 125,000 —

At the market offering costs — — (241 )

Net increase (decrease) in cash and cash equivalents (3,904 ) (89,799 ) 90,307

Supplemental cash flow information

Equipment acquired under finance lease $ 952 $ 40 $ 289

See accompanying Notes to Consolidated Financial Statements

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OMEROS CORPORATION

NOTESTO CONSOLIDATED FINANCIAL STATEMENTS

Note1—Organization and Basis of Presentation

General

Omeros Corporation (“Omeros,” the “Company” or “we”) is a clinical-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting immunologic disorders including complement-mediated diseases, cancers, and addictive and compulsive disorders. We marketed our first drug product OMIDRIA® (phenylephrine and ketorolac intraocular solution) 1% / 0.3% for use during cataract surgery or intraocular lens replacement in the United States (the “U.S.”) until we sold OMIDRIA and related business assets on December 23, 2021 (see “Sale of OMIDRIA Assets” below for additional information).

Our pipeline of clinical-stage development programs includes: narsoplimab, our antibody targeting mannan-binding lectin-associated serine protease 2 ("MASP-2"), the effector enzyme of the lectin pathway of complement; OMS1029, our long-acting antibody targeting MASP-2;OMS906, our antibody targeting mannan-binding lectin-associated serine protease-3 ("MASP-3"), the key activator of the alternative pathway of complement; and OMS527, our phosphodiesterase 7 ("PDE7") inhibitor program.

Clinical development of narsoplimab is currently focused primarily on hematopoietic stem cell transplant-associated thrombotic microangiopathy ("TA-TMA"). Our Biologics License Application ("BLA") for narsoplimab in TA-TMA is anticipated to be resubmitted with additional information to support potential approval of narsoplimab in this indication. In October 2023, we announced the results of a pre-specified interim analysis of our Phase 3 ARTEMIS-IGAN trial evaluating narsoplimab for the treatment of immunoglobulin A ("IgA") nephropathy. Topline results showed that narsoplimab did not reach statistically significant improvement over placebo on the primary endpoint of reduction in proteinuria. Based on this result, we have discontinued the ARTEMIS-IGAN clinical trial.

Phase 1 and Phase 2 clinical programs are underway in our other clinical-stage assets.

Sale of OMIDRIA Assets

On December 23, 2021, we closed on an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Rayner Surgical Inc. (“Rayner”) for the sale of our commercial product OMIDRIA. Rayner paid us $126.0 million in cash at closing, and we retained all outstanding accounts receivable, accounts payable and accrued expenses as of the closing date. Additionally, we are entitled to future royalty payments on net sales of OMIDRIA.

Under the Asset Purchase Agreement, Omeros is entitled to receive a milestone payment of $200.0 million (the “Milestone Payment”) following an event (the "Milestone Event") that establishes separate payment for OMIDRIA for a continuous period of at least four years when furnished in the ambulatory surgery center (“ASC”) setting. In December 2022, the Milestone Event occurred and we recorded a $200.0 million milestone receivable. We received the Milestone Payment in February 2023.

As a result of the divestiture, the results of OMIDRIA operations (e.g., revenues and operating costs) have been reclassified to discontinued operations in our consolidated statements of operations and comprehensive income (loss) and excluded from continuing operations for all periods presented (See“Note 7 – Discontinued Operations – Sale of OMIDRIA ”).

Basis of Presentation

Our consolidated financial statements include the financial position and results of operations of Omeros and our wholly owned subsidiaries. All inter-company transactions have been eliminated. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”).

Liquidity and Capital Resources

As of December 31, 2023, we had cash, cash equivalents and short-term investments of $171.8 million. Our cash provided by operations for the year ended December 31, 2023 was $74.7 million and included our 2023 net loss for the year of $117.8 million and collection of the $200.0 million Milestone Payment in the first quarter of 2023. We extinguished $95.0 million outstanding of convertible senior notes at maturity in November 2023. In February 2024, we received $115.5 million upon the sale to DRI Healthcare Acquisition LP ("DRI") of substantially all of our expected remaining U.S.-only Rayner OMIDRIA royalty receipts payable through December 31, 2031 (see “Note 8 - OMIDRIA Royalty Obligation”).

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Historically, we have incurred net losses from continuing operations and negative operating cash flows. We have not yet established an ongoing source of revenue sufficient to cover our operating costs; therefore, we potentially need to continue to raise additional capital to accomplish our business plan and to retire our outstanding convertible senior notes due in 2026. We plan to continue to fund our operations for at least the next twelve months with our existing cash and investments and the $115.5 million we received in February 2024 from DRI. We have a sales agreement to sell shares of our common stock, from time to time, in an “at the market” equity offering facility through which we may offer and sell shares of our common stock equaling an aggregate amount up to $150.0 million. Should it be determined to be strategically advantageous, we could pursue debt financings as well as public and private offerings of our equity securities, similar to those we have previously completed, or other strategic transactions, which may include licensing a portion of our existing technology. Should it be necessary to manage our operating expenses, we could also reduce our projected cash requirements by delaying clinical trials, reducing selected research and development efforts, or implementing other restructuring activities.

Segments

We operate in one segment. Management uses cash flow as the primary measure to manage our business and does not segment our business for internal reporting or decision-making.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant items subject to such estimates include OMIDRIA contract royalty asset valuation, stock-based compensation expense, and accruals for clinical trials and manufacturing of drug product. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances; however, actual results could differ from these estimates.

Note2—Significant Accounting Policies

Discontinued Operations

We review the presentation of planned or completed business dispositions in the consolidated financial statements based on the available information and events that have occurred. The review consists of evaluating whether the business meets the definition of a component for which the operations and cash flows are clearly distinguishable from the other components of the business and, if so, whether it is anticipated that after the disposal the cash flows of the component would be eliminated from continuing operations and whether the disposition represents a strategic shift that has a major effect on operations and financial results.

Planned or completed business dispositions are presented as discontinued operations when all the criteria described above are met. For those divestitures that qualify as discontinued operations, all comparative periods presented are reclassified in the consolidated balance sheets. Additionally, the results of operations of a discontinued operation are reclassified to income from discontinued operations, net of tax, for all periods presented in the consolidated statements of operations and comprehensive income (loss). Results of discontinued operations include all revenues and expenses directly derived from such businesses. General corporate overhead is not allocated to discontinued operations. The OMIDRIA asset sale to Rayner qualifies as a discontinued operation and has been presented as such for all reporting periods presented. The Company included information regarding cash flows from discontinued operations (see “Note 7 – Discontinued Operations – Sale of OMIDRIA”).

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OMIDRIA Royalties, Milestones and Contract Royalty Assets

We have rights to receive future royalties from Rayner on OMIDRIA net sales at royalty rates that vary based on geography and certain regulatory contingencies. Therefore, future OMIDRIA royalties are treated as variable consideration. The sale of OMIDRIA qualified as an asset sale under GAAP. To measure the OMIDRIA contract royalty asset, we used the expected value approach which is the sum of the discounted probability-weighted royalty payments, we would receive using a range of potential outcomes, to the extent that it is probable that a significant reversal in the amount of cumulative income recognized will not occur. As contemplated by the Asset Purchase Agreement, the royalty rate applicable to U.S. net sales of OMIDRIA was reduced from 50% to 30% upon the occurrence, in December 2022, of the event triggering the $200.0 million Milestone Payment. The reduction in our royalty rate to 30% continues until the expiration or termination of the last issued and unexpired U.S. patent, which we expect to occur no earlier than 2035. Consequently, we revalued the OMIDRIA contract royalty asset using the 30% royalty rate on U.S. net sales and adjusted the probability weighted outcomes to reflect the occurrence of the Milestone Event. Royalties earned are recorded as a reduction to the OMIDRIA contract royalty asset. The amount recorded in discontinued operations in future periods will reflect interest earned on the outstanding OMIDRIA contract royalty asset at 11.0% and any amounts we receive that are different from the expected royalties. The OMIDRIA contract royalty asset is re-measured periodically using the expected value approach based on actual results and future expectations. Any required adjustment to the OMIDRIA contract royalty asset is recorded in discontinued operations.

OMIDRIA Royalty Obligation

On September 30, 2022, we sold to DRI an interest in a portion of our future OMIDRIA royalty receipts for a purchase price of $125.0 million and recorded as an “OMIDRIA royalty obligation” on our consolidated balance sheet. The liability is amortized over the term of the arrangement using the implied effective interest rate of 9.4%. Interest expense is recorded as a component of continuing operations.

To the extent our estimates of future royalties are less than previous estimates, we will adjust the carrying amount of the OMIDRIA royalty obligation to the present value of the revised estimated cash flows, discounted at the effective interest rate utilizing the cumulative catch-up method. The adjustment would be recognized as a component of net income (loss) from continuing operations (see “Note 8 - OMIDRIA Royalty Obligation”).

Cash and Cash Equivalents, Short-Term Investments and Restricted Investments

Cash and cash equivalents include highly liquid investments with a maturity of three months or less on the date of purchase which can be easily converted into cash without a significant impact to their value. Short-term investment securities are classified as held-to-maturity. Investments classified as held-to-maturity are carried at cost. Amortization, accretion, interest, and dividends, realized gains and losses and declines in value judged to be other-than-temporary are included in other income. The cost of securities sold is based on the specific-identification method. Investments with maturities of less than one year, or those for which management intends to use the investments to fund current operations, are included in current assets. We evaluate whether an investment is other-than-temporarily impaired based on the specific facts and circumstances. Factors that are considered in determining whether an other-than-temporary decline in value has occurred include: the market value of the security in relation to its cost basis; the financial condition of the investee; and the intent and ability to retain the investment for a sufficient period of time to allow for recovery in the market value of the investment. Restricted investments held in money-market funds include security deposits held by our landlord.

Investment income, which is included as a component of other income, consists primarily of interest earned.

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Inventory

We expense inventory costs related to product candidates as research and development expenses until regulatory approval is reasonably assured in the U.S. or the European Union (“EU”). Once approval is reasonably assured, costs, including amounts related to third-party manufacturing, transportation and internal labor and overhead, will be capitalized.

Receivables

Receivables at December 31, 2023 primarily consist of royalties receivable from Rayner. Receivables at December 31, 2022 also included the $200.0 million Milestone Payment which we received in February 2023. Considering the nature of our receivables, we concluded an allowance for doubtful accounts was not necessary as of December 31, 2023 and 2022, respectively.

Property and Equipment, Net

Property and equipment are stated at cost, and depreciation is calculated using the straight-line method over the estimated useful life of the assets, which is generally three to 10 years. Equipment acquired through finance leases is recorded as property and equipment and is amortized over the shorter of the useful lives of the related assets or the lease term. Expenditures for repairs and maintenance are expensed as incurred.

Convertible Senior Notes

On January 1, 2021, we adopted Accounting Standards Update (“ASU”) 2020-06,Debt—Debt with Conversion Options (Subtopic 470.20and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) on a modified retrospective basis. ASU 2020-06 removed the separate liability and equity accounting for our convertible senior notes that was required under previous guidance and allows us to account for our convertible senior notes wholly as debt. Upon adoption, we removed the equity component allocated to debt issuance costs.

Transactions involving contemporaneous exchanges of cash between the same debtor and creditor in connection with the issuance of a new debt obligation and satisfaction of an existing debt obligation are evaluated as a modification or an extinguishment depending on whether the exchange is determined to have substantially different terms. We extinguished the 6.25% convertible senior notes (the “2023 Notes”) at par upon maturity on November 15, 2023. In December 2023, we repurchased $9.1 million par value of our 5.25% convertible senior notes (“2026 Notes”) at a discount, realizing a $4.1 million non-cash gain on extinguishment.

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Impairment of Long-Lived Assets

We assess the impairment of long-lived assets, whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Recoverability of these assets is measured by comparing the carrying value to future undiscounted cash flows that the asset is expected to generate. If the asset is impaired, the amount of any impairment will be reflected in the results of operations in the period of impairment. We have not recognized any impairment losses for the years ended December 31, 2023, 2022 and 2021.

Revenue Recognition

When we enter into a customer contract, we perform the following five steps: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation.

Prior to the sale of OMIDRIA to Rayner, we recorded product sales as revenue when the product was delivered to our wholesalers and title for the product was transferred. Product sales were recorded net of wholesaler distribution fees and estimated chargebacks, rebates, returns and purchase-volume discounts.

Research and Development

Research and development expenses are comprised primarily of contracted research, clinical trial study and manufacturing costs prior to approval; consulting services; contract milestones; materials and supplies; costs for personnel, including salaries, benefits and stock compensation; depreciation; an allocation of our occupancy costs; and other expenses incurred to sustain our overall research and development programs. Advance payments for goods or services that will be used for future research and development activities are deferred and then recognized as an expense as the related goods are delivered or the services are performed. All other research and development costs are expensed as incurred.

Selling, General and Administrative

Selling, general and administrative expenses are comprised primarily of marketing and selling expenses; professional and legal services; patent costs; and salaries, benefits, and stock-compensation costs for sales, marketing, and other personnel not directly engaged in research and development. Additionally, selling, general and administrative expenses include depreciation; an allocation of our occupancy costs; and other general corporate expenses. Advertising costs are expensed as incurred. We had no advertising costs during the years ended December 31, 2023 and 2022. For the year ended December 31, 2021, we incurred $0.8 million in advertising costs related to our sales of OMIDRIA.

Income Taxes

Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized.

Stock-Based Compensation

Stock-based compensation expense is recognized for all share-based payments, including grants of stock option awards and restricted stock units (“RSU”) based on estimated fair values. The fair value of our stock is calculated using the Black-Scholes option-pricing model, which requires judgmental assumptions around volatility, forfeiture rates, risk-free rate and expected term. Compensation expense is recognized over the requisite service periods, which is generally the vesting period, using the straight-line method. Forfeiture expense is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates.

Common Stock Repurchases

We may repurchase shares of our common stock from time to time under authorization made by our Board of Directors. Under applicable Washington State law, repurchased shares are retired and not presented separately as treasury stock on the consolidated financial statements.

Accumulated Other Comprehensive Income (Loss)

Accumulated other comprehensive income (loss) is comprised of net income (loss) and certain changes in equity that are excluded from net income (loss). There was no difference between comprehensive income (loss) and net income (loss) for the years ended December 31, 2023, 2022 and 2021.

Financial Instruments and Concentrations of Credit Risk