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, Product Candidates, Programs and Operations

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

YARTEMLEA is our only commercialized product and was approved by FDA for commercial sale in the United States in December 2025. Our near‐term commercial prospects are highly dependent on YARTEMLEA in its approved indication, and any adverse developments affecting YARTEMLEA could have a disproportionate adverse effect on our business. We will need to generate substantial product revenue from YARTEMLEA to fund our operations fully and to achieve and sustain profitability. We may be unable to successfully commercialize YARTEMLEA for a number of reasons, including:

● our limited experience in marketing, selling, and distributing YARTEMLEA;

● an unknown safety risk;

If we are not able to successfully commercialize YARTEMLEA for these or other reasons, our ability to generate sufficient revenues from product sales to achieve profitability will be adversely affected and the market price of our common stock could decline significantly.

If YARTEMLEA or any other 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 YARTEMLEA or 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.

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 product candidates may be impaired and there could be a material adverse effect on our business, financial condition, results of operations and growth prospects and the trading price of our stock could decline.

Our ability to realize further value from zaltenibart depends on the development and commercialization efforts of Novo Nordisk.

Our ability to realize further value from zaltenibart depends on Novo Nordisk’s successful development, regulatory approval, and commercialization of zaltenibart. As a result of our APLA with Novo Nordisk, Novo Nordisk now controls key decisions regarding the development, regulatory strategy, manufacturing, and commercialization of zaltenibart. This means that whether we receive payments potentially due to us under the terms of the APLA, and the magnitude of such payments, depends on Novo Nordisk’s ability to advance development and obtain regulatory approval of zaltenibart. Novo Nordisk may not successfully advance development, obtain regulatory approval or commercialize zaltenibart products for many reasons, including that it may determine not to pursue development in certain indications, may delay or discontinue development programs, or may prioritize other programs in its pipeline.

In addition, the potential consideration we may yet receive under the APLA consists of development milestones, sales milestones, and royalties on net sales of products containing zaltenibart. These payments are contingent on factors outside of our control such as the successful development, regulatory approval, and commercialization of zaltenibart, any of which may never occur. If Novo Nordisk does not successfully develop or commercialize zaltenibart, or if commercialization is less successful than anticipated, we may receive substantially less in milestone and royalty payments than we currently expect or no additional payments at all. Further, even if products containing zaltenibart are successfully commercialized, the amount of royalty revenue we receive may vary significantly from period to period and may be affected by factors such as pricing, reimbursement, sales volumes, competition, and other market conditions. In sum, our ability to realize further value from this transaction could be materially adversely affected and, in turn, our future operating results and financial condition could be materially adversely affected.

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 products and product candidates or to continue our other preclinical development programs.

Our operations have consumed substantial amounts of cash since our incorporation, As of December 31, 2025, we had cash, cash equivalents and short-term investments of $171.8 million. Our cash used in operations for the year ended December 31, 2025 was $116.1 million and our net loss for the year ended December 31, 2025 was $3.4 million. We expect to continue to spend substantial amounts to:

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

● commercialize YARTEMLEA and any other product candidates for which we may receive regulatory approval in the future;

● support YARTEMLEA sales and marketing;

● continue our research and development programs; and

● make principal, interest and fee payments as required under our convertible senior notes maturing on June 15, 2029 (the “2029 Notes”).

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

Our indebtedness and liabilities and any future indebtedness 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, 2025, we had $17.1 million total aggregate principal amount outstanding of our 5.25% convertible senior notes due on February 15, 2026 (the “2026 Notes”), which have since matured and been repaid in full, $70.8 million total aggregate principal amount outstanding of our 2029 Notes, and approximately $1.2 million of outstanding finance lease obligations. We may incur additional indebtedness to meet future financing needs, which may have the effect of:

● 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;

● diluting the interests of our existing stockholders as a result of issuing shares of our common stock upon any conversion of the 2029 Notes or additional convertible notes that we may issue in the future;

● 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 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 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.

22

Table of Contents

Failure to obtain and maintain regulatory approval in the EU or other foreign jurisdictions would prevent us from commercializing and marketing YARTEMLEA or future commercialized products.

We intend to market YARTEMLEA and any of our product candidates that are approved in the future outside the U.S. In order to market our products in non-U.S. jurisdictions, we or our partners must obtain separate regulatory approvals and comply with numerous and varying regulatory requirements. The regulatory approval procedure varies among countries and can involve additional testing and data review. The requirements governing marketing authorization, the conduct of clinical trials, pricing and reimbursement vary from country to country. Approval by FDA does not ensure approval by the EMA, and approval by one foreign regulatory authority does not ensure approval by regulatory agencies in other foreign countries or by FDA. The time required to obtain regulatory approval outside the U.S. and EU may differ from that required to obtain FDA or EU approval. 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.

We may face a variety of risks associated with international operations that, if realized, could materially adversely affect our business.

We may be subject to additional risks for YARTEMLEA or any of our product candidates that are marketed outside the U.S., including:

● reduced protection for intellectual property rights;

● unexpected changes in tariffs, trade barriers, and regulatory requirements;

Any of these risks, if realized, could increase our operating expenses and reduce our revenues.

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 level and timing of commercial sales of YARTEMLEA, as well as our product candidates if and when approved or commercialized;

● the availability and adequacy of payer reimbursement for YARTEMLEA;

● the amount of YARTEMLEA chargebacks, rebates and product returns;

● the extent and magnitude of certain milestone and royalty payments to which we may be entitled based on Novo Nordisk’s development, commercialization, and net sales of zaltenibart;

● the extent and magnitude of certain payments to which we may be entitled based on net sales of OMIDRIA by Rayner Surgical, Inc. (“Rayner”) depend on Rayner’s ability to successfully market and sell OMIDRIA and 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, products and product candidates, or in preparation for potential commercialization of our product candidates; and

● whether we are able to obtain marketing approval for any of our product 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.

23

Table of Contents

Significant changes to the size, structure, powers and operations of the U.S. federal government, as well as policy actions by the U.S. federal government, may cause economic disruptions or changes in the regulatory environment that could, in turn, adversely impact our business, results of operations and financial condition.

The current U.S. administration has implemented significant changes to the size and scope of the federal government to achieve stated goals including reducing the federal budget deficit and national debt, improving the efficiency of government operations, and promoting innovation and economic growth. To date, these efforts have been carried out through a mix of executive actions aimed at eliminating or modifying federal agency and federal program funding, reducing the size of the federal workforce, reducing or altering the scope of activities conducted by, and possibly eliminating, various federal agencies and bureaus. These changes may have varied effects on the economy that are difficult to predict. For instance, the delivery of government services and the distribution of federal program funds and benefits may be disrupted or, in some cases, eliminated as a result of funding cuts, recasting of federal agency mandates or a substantial reduction of the federal workforce. We rely on the availability, predictability and efficiency of federal agencies including FDA, NIDA and others in connection with the operation of our business and programs. Our business, financial condition and results of operations could be materially and adversely affected by disruptions affecting these or other agencies in areas relevant to our programs and operations.

In addition, policy actions by the U.S. administration, including broad imposition of tariffs, may have an adverse impact on our business. Increased tariffs on critical raw materials, components, and finished goods could raise our production costs, disrupt our supply chain, and reduce our competitiveness in the marketplace. If these or other policy changes continue or expand, we may face increased costs. Although we cannot predict the full extent of these impacts, any prolonged disruption could adversely affect our business, financial condition, and results of operations.

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

Both before and after approval of any product, we and our suppliers, contract manufacturers and clinical investigators are subject to extensive regulation by governmental authorities in the U.S. and other countries, covering, among other things, testing, manufacturing, quality control, clinical trials, post-marketing studies, reporting, risk management plans, labeling, advertising, promotion, distribution, import and export, governmental pricing, price reporting and rebate requirements. Failure to comply with applicable requirements could result in one or more of the following actions: warning letters; unanticipated expenditures; delays in approval or refusal to approve a product candidate; product recall or seizure; interruption of manufacturing or clinical trials; operating or marketing restrictions; injunctions; criminal prosecution and civil or criminal penalties including fines and other monetary penalties; adverse publicity; and disruptions to our business. Further, government investigations into potential violations of these laws would require us to expend considerable resources and face adverse publicity and the potential disruption of our business even if we are ultimately found not to have committed a violation.

Obtaining FDA approval of our product candidates requires substantial time, effort and financial resources and may be subject to both expected and unforeseen delays, and there can be no assurance that any approval will be granted on any of our product candidates on a timely basis, if at all. Even 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 product 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 product candidates beyond that which we currently contemplate for regulatory approval, if we are unable to complete our clinical trials or other testing successfully, or if the results of these and other trials or tests fail to demonstrate efficacy or raise safety concerns, we may face substantial additional expenses, be delayed in obtaining marketing approval for our product candidates or may never obtain marketing approval.

We are also required to comply with extensive governmental regulatory requirements after a product has received marketing authorization. Governing regulatory authorities may require post-marketing studies that may negatively impact the commercial viability of a product. Once on the market, a product may become associated with previously undetected adverse effects and/or may develop manufacturing difficulties. We are required to comply with other post-marketing requirements including cGMP, 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.

Failure to comply with any YARTEMLEA post-marketing requirement or commitment could materially adversely affect the commercial prospects of YARTEMLEA and our business.

Following FDA approval of YARTEMLEA, we remain subject to ongoing regulatory oversight, including a post-marketing requirement and post-marketing commitments. These include, among other obligations, a post-marketing requirement safety registry and post-marketing commitments related to a pediatric PK/PD study and CMC. The associated timelines extend over multiple years.

Failure to satisfy these obligations in a timely manner, or at all, could result in actions from the FDA such as warning letters, misbranding findings, monetary penalties, or potentially even suspending or withdrawing approval for YARTEMLEA. In addition, the emergence of new safety, efficacy, or manufacturing information, whether from required studies, real-world use, or regulatory review, could lead the FDA or other regulatory authorities to impose labeling changes, restrict use, require additional studies, or, in more serious cases, suspend or withdraw approval. Any such actions could materially and adversely affect the commercial prospects of YARTEMLEA and our business.

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

Existing regulatory policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates or affect the pricing and other terms on which we may sell approved products. 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.

24

Table of Contents

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 measures designed to contain the price of prescription drugs or other reforms may prevent us from being able to generate sufficient revenue, attain and/or maintain profitability or commercialize our product candidates. We cannot be sure whether additional legislative and regulatory changes, including as a result of the U.S. administration, will be enacted, whether existing legislation and regulatory proposals will be implemented, interpreted or enforced as anticipated, or what the impact of such changes on our product or product candidates, if any, may be.

We have no internal capacity to manufacture commercial or clinical supplies of YARTEMLEA or our product candidates, intend to continue to rely solely on third-party manufacturers, and thus may be materially harmed by issues impacting our contract manufacturers or our relationship with our contract manufacturers.

We rely and intend to continue to rely on third-party manufacturers to produce quantities of YARTEMLEA and clinical drug supplies of our product candidates that are needed for clinical trials and to support NDAs, BLAs, or similar applications to regulatory authorities seeking marketing approval for our product candidates, as well as to produce inventory of our product candidates for commercial use in anticipation of marketing approval. 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 product 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, YARTEMLEA, OMS1029, and OncotoX-AML are biologic drug products and other product candidates from certain of our programs, including but not limited to MASP-2, MASP-3, Oncotox-AML, and T-CAT, 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.

25

Table of Contents

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

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 YARTEMLEA or our product candidates may not be available on commercially reasonable terms, or at all, which may adversely affect sales of YARTEMLEA or development and commercialization of our product candidates.

We and our third-party manufacturers must obtain from third-party suppliers the APIs, excipients, and/or other raw materials plus primary and secondary packaging materials necessary for our contract manufacturers to produce YARTEMLEA and our product candidates for our clinical trials and, to the extent approved or commercialized, for commercial distribution. Although we have entered or intend to enter into agreements with third-party suppliers that will guarantee the availability and timely delivery of APIs, excipients, test kits and materials for YARTEMLEA and our product 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. If we or our third-party manufacturers are unable to obtain the quantities of the ingredients, excipients or materials that are necessary for the manufacture of commercial supplies of YARTEMLEA, our ability to generate revenue from the sale of YARTEMLEA would be materially and adversely affected. Additionally, if Novo Nordisk or its third-party manufacturers are unable to obtain the quantities of the ingredients, excipients or materials that are necessary for the manufacture of zaltenibart for clinical development or commercial use, if approved by regulatory authorities, our receipt of certain milestones and the amount of royalty income we could expect to receive would be materially and adversely affected. Further, if we or our third-party manufacturers are unable to obtain APIs, excipients, test kits and materials as necessary for our clinical trials or for the manufacture of commercial supplies of our product candidates, if approved, potential regulatory approval or commercialization would be delayed, which would materially and adversely affect our ability to generate revenue from the sale of our product candidates.

26

Table of Contents

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

We cannot predict whether we will encounter problems with any of our completed, ongoing or planned clinical trials or clinical data collection protocols that will cause regulatory agencies, institutional review boards or ethics committees, or us to delay our clinical trials or suspend or delay the analysis of the data from those trials. Clinical trials and clinical data protocols 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 product 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, or outbreaks of contagious disease such as the COVID-19 pandemic, which previously slowed enrollment in our clinical trials of YARTEMLEA;

● 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 product candidate, poorly executed testing, a failure of a clinical site to adhere to the clinical protocol or to follow GCP or other study requirements, an unacceptable study design or other problems;

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

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

● the need to qualify new suppliers of product 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.

27

Table of Contents

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 product 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 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 product candidate. Any delays in completing our clinical trials could increase our development costs, could slow down our product development and regulatory submission process, could delay our receipt of product revenue and could make it difficult to raise additional capital. In addition, significant clinical trial delays also could allow our competitors to bring products to market before we do and impair our ability to commercialize our future products, potentially harming our business.

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

We have limited resources and must focus on the product candidates and clinical and preclinical development programs that we believe are the most promising. As a result, we may forgo or delay the pursuit of opportunities with other product candidates or other indications that later prove to have greater commercial potential and may not be able to progress development programs as rapidly as otherwise possible. Further, if we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that 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 obligations under the Transition Services Agreement require us to utilize significant internal resources that could otherwise be used to advance our other programs.

In connection with the APLA, we entered into a Transition Services Agreement under which we are required to provide certain transition services to facilitate the transfer of the acquired assets and liabilities under the APLA and to provide for the continued operation of relevant studies and program activities during the applicable term, subject to reimbursement by Novo Nordisk.

Providing these services requires us to devote management time and internal personnel and other resources that could otherwise be used to advance our drug candidates, programs, and operations. As a result, our obligations under the Transition Services Agreement may divert resources away from our drug candidates, programs, and operations and may delay or limit our ability to advance these drug candidates, programs, and operations.

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

We must successfully complete preclinical testing, which may include demonstrating efficacy and the lack of toxicity in established animal models, before commencing clinical trials for any product candidate. Many pharmaceutical and biological product candidates do not successfully complete preclinical testing. There can be no assurance that positive results from preclinical studies will be predictive of results obtained from subsequent preclinical studies or clinical trials.

28

Table of Contents

Even if preclinical testing is successfully completed, we cannot be certain that any product candidates that do advance into clinical trials will successfully demonstrate safety and efficacy in clinical trials. Even if we achieve positive results in early clinical trials, they may not be predictive of the results in later trials, and safety and/or efficacy outcomes of early clinical trials may not be consistent with outcomes of subsequent clinical trials, or FDA may take the position that despite the successful outcomes, they do not demonstrate the safety and effectiveness of our product candidates to FDA’s satisfaction. There can be no assurance that we will be able to successfully commercialize our current or future product candidates or to meet our expectations with respect to revenues or profits from such products.

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

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

We may initiate or become subject to litigation regarding patents and other intellectual property rights. Patent infringement litigation involves many complex technical and legal issues and its outcome is often difficult to predict and the risk involved in doing so can be substantial. 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 product 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 products and product candidates. These lawsuits are costly and could affect our results of operations and divert the attention of managerial and technical personnel. There is a risk that a court would decide that we, or our contract manufacturers, are infringing the third party’s patents and would order us or our contractors to stop the activities covered by the patents. In addition, if we or our contract manufacturers are found to have violated a third party’s patent, we or our contract manufacturers could be ordered to pay damages to the other party. We have agreed or may 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 products and product candidates or methods of use either do not infringe the patent claims of the relevant patent or that the patent claims are invalid, and we might be unable to do this. Proving invalidity, in particular, is difficult since it requires clear and convincing evidence to overcome the presumption of validity enjoyed by issued patents.

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

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

29

Table of Contents

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 products and product candidates and/or materially harm our business.

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

We also may rely on trade secrets to protect our technologies or product 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.

30

Table of Contents

Novo Nordisk controls significant aspects of the prosecution, maintenance, and enforcement of key intellectual property covering zaltenibart products, and its failure to protect, enforce, or maintain that intellectual property could adversely affect the commercial value of zaltenibart products and, in turn, the milestone or royalty payments we receive.

Under our APLA with Novo Nordisk, we transferred certain patent rights and other intellectual property relating to zaltenibart and granted Novo Nordisk rights to exploit that intellectual property. As a result, Novo Nordisk controls significant aspects of the prosecution, maintenance, and enforcement of key intellectual property covering zaltenibart products.

Because Novo Nordisk controls these activities, we have limited ability to influence how such intellectual property is prosecuted, maintained, defended, or enforced. Novo Nordisk may decide not to pursue, enforce, or defend certain intellectual property rights or may do so in a manner with which we disagree. If intellectual property protecting zaltenibart products is not adequately protected, enforced, or maintained, the commercial value of zaltenibart products and, in turn, the milestone payments or royalties we may receive could be adversely affected.

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 YARTEMLEA or 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 transition to a commercial‐stage company requires operational and commercial expertise, and the loss of key personnel could disrupt our ability to execute our business strategy. 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.

31

Table of Contents

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 products and product candidates. In addition, product liability insurance for the biopharmaceutical industry is generally expensive to the extent it is available at all. There can be no assurance that we will be able to obtain or maintain such insurance on acceptable terms for YARTEMLEA or any other product we bring to market. Further, our product liability insurance coverage may not provide coverage for or may be insufficient to reimburse us for any or all expenses or losses we may suffer. A successful claim against us with respect to uninsured liabilities or in excess of insurance coverage could have a material adverse effect on our business, financial condition and results of operations.

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

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

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.

Our use of artificial intelligence exposes us to deficient outputs, unintentional disclosures, and an evolving regulatory landscape.

We use artificial intelligence (“AI”), including machine learning and generative AI technologies, in various aspects of our business, including research and development, data analysis, and certain internal functions. Use of AI systems presents risks and uncertainties, as they may generate inaccurate, incomplete, or biased outputs. Reliance on such deficient outputs could lead to flawed analyses, operational errors, or suboptimal decision-making, including in connection with scientific, regulatory, or commercial activities, which, in turn, could adversely affect our business, financial condition, and results of operations.

In addition, some of the AI tools we use are provided by third-party vendors, and our use of these technologies may involve the processing of proprietary, confidential, or other sensitive data. If such data were improperly disclosed, accessed by unauthorized parties, incorporated into external AI training models, or otherwise misused, our intellectual property, competitive position, and reputation could be harmed. Our use of AI also exposes us to evolving legal and regulatory requirements relating to data privacy, cybersecurity, intellectual property, and the use of automated decision-making technologies, and compliance with these requirements may increase our costs or limit our ability to deploy AI tools effectively. If we fail to manage these risks effectively, our business, financial condition, and results of operations could be adversely affected.

Further, the landscape of available AI is rapidly evolving. If our competitors adopt more effective AI, we may be adversely affected by the competitive disadvantage.

The availability of royalties from Rayner is dependent on Rayner’s net sales of OMIDRIA and may be of lesser magnitude than anticipated or may not become payable at all and we do not expect to receive a sales-based milestone payment from DRI.

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. We retain the right to receive all royalties payable by Rayner on any net sales of OMIDRIA outside the U.S. as well as royalties on global net sales of OMIDRIA payable from and after December 31, 2031. However, the availability of royalties from Rayner is dependent on Rayner’s net sales of OMIDRIA and may be of lesser magnitude than anticipated or may not become payable at all. Additionally, while we are entitled to receive 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 prior to January 1, 2028, we do not expect to receive this milestone based on current U.S. net sales of OMIDRIA. If the payments we receive from Rayner and/or DRI are less than we anticipate, this may adversely impact our financial condition and results of operation.

As a non-accelerated filer, we are not required to comply with the auditor attestation requirements of the Sarbanes-Oxley Act.

We are a non-accelerated filer under the Exchange Act and, therefore, we are not required to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act. Therefore, our internal control 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.

32

Table of Contents

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, 2025, the closing price of our stock ranged from as high as $17.18 per share and as low as $2.97 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 18.3 million shares of common stock were subject to outstanding options as of December 31, 2025 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, 2025, we also had approximately 3.9 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 2029 Notes, such conversion would dilute the ownership interests of existing stockholders. If the holders of outstanding options 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 2029 Notes, our shareholders would experience dilution and the market price of our common stock could decline.

33

Table of Contents

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 have no intention of 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.

Our ability to use our net operating loss carryforwards and certain other tax attributes to offset taxable income or taxes may be limited.

We have incurred substantial losses during our history, and we may never become or remain profitable. As of December 31, 2025, we had U.S. federal net operating loss (“NOL”) carryforwards of approximately $386.4 million and state NOL carryforwards of approximately $229.8 million. Pre-2018 U.S. federal NOL carryforwards of $45.4 million expire between 2035 and 2037. Under the Internal Revenue Code of 1986, as amended (the “Code”), our post-2018 U.S. federal NOL carryforwards will not expire and may be carried forward indefinitely but the deductibility of such NOL carryforwards is limited to no more than 80% of current year taxable income (with certain adjustments). In addition, under Sections 382 and 383 of the Code, if a corporation undergoes an “ownership change,” generally defined as a greater than 50 percentage point change (by value) in its equity ownership by certain stockholders over a three-year period, the corporation’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income or taxes may be limited. We completed a Section 382 study through December 31, 2025, which showed no limitation on the use of our NOLs or tax credits. However, there may be ownership changes since the completion of that study, including in connection with this offering or as a result of subsequent changes in our stock ownership, some of which may be outside of our control. As a result, if we undergo an ownership change, and our ability to use our pre-change NOL carryforwards and other pre-change tax attributes (such as research tax credits) to offset our post-change income or taxes is limited, it would harm our future results of operations by effectively increasing our future tax obligations. Similar provisions of state tax law may also apply to limit our use of accumulated state tax attributes. In addition, at the state level, there may be periods during which the use of NOL carryforwards is suspended or otherwise limited, which could accelerate or permanently increase our state taxes owed. As a result, even if we attain profitability, we may be unable to use all or a material portion of our NOL carryforwards and other tax attributes, which could adversely affect our future cash flows.

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 variety 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 106,949 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 1,134 square feet of laboratory space that we are subleasing to third parties. The lease term for our space is through November 2027. We also have two options to extend the lease term, each by five years. The annual base rent due under the lease for our principal office and laboratory space is $6.6 million for 2026, and $5.7 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.

34

Table of Contents

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 27, 2026, there were approximately 71,996,171 shares of our common stock outstanding, which were held by 76 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

On May 12, 2025, under note conversion agreements, two holders converted $10.0 million aggregate principal amount of their 2026 Notes into 2,819,866 shares of our common stock (the “Equitization Transaction”) in three tranches. We did not receive new cash proceeds in connection with the Equitization Transaction. The shares of common stock were issued in reliance on the exemption from registration provided under Section 4(a)(2) of the Securities Act.

Issuer Purchases of Equity Securities

On November 29, 2025, the Board of Directors approved a new share repurchase program under which we are permitted to repurchase from time to time up to $100.0 million of our common stock in the open market or through privately negotiated transactions. We did not repurchase any shares of common stock during the year ended December 31, 2025.

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, 2020 and ending December 31, 2025. This graph assumes that $100 was invested on December 31, 2020 in our common stock, the Nasdaq Biotechnology Index and the Nasdaq U.S. Benchmark TR Index. It also assumes that any dividends, if any, were reinvested. The data shown in the following graph are not necessarily indicative of future stock price performance.

35

Table of Contents

The foregoing information in this stock performance graph 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.

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.

36

Table of Contents

Overview

We are an innovative, commercial-stage biotechnology company that discovers and develops first-in-class protein and small-molecule therapeutics for large-market and orphan indications, with particular emphasis on complement-mediated diseases, cancers, and addictive or 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. We are focused on development of therapeutics to treat diseases associated with the lectin and/or alternative pathways of complement. We are 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. We are 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 product and product candidate in our pipeline of complement-targeted therapeutics is narsoplimab (OMS721), a proprietary, patented human monoclonal antibody targeting MASP-2, the key activator of the lectin pathway of complement. Our lead lectin pathway inhibitor YARTEMLEA® (narsoplimab-wuug) is FDA-approved and commercially available in the U.S. for the treatment of TA-TMA in adult and pediatric patients aged two years and older. An MAA for YARTEMLEA in TA-TMA is currently under review by the EMA. Clinical development of narsoplimab is anticipated to continue to expand the approved label in TA-TMA and to develop the drug in additional indications. Clinical development efforts have previously been directed to ARDS, including severe acute COVID-19, which can result in PASC. We are also developing OMS1029, our long-acting antibody targeting MASP-2, which we expect will be well-suited to indications requiring long-term, chronic administration. In addition, we have directed efforts towards the development of small-molecule inhibitors of MASP-2, designed for oral administration. 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”.

Commercial Product – YARTEMLEA

Our commercial product, YARTEMLEA, is the first and only approved inhibitor of the lectin pathway of complement. On December 23, 2025, FDA approved YARTEMLEA for the treatment of TA-TMA in adults and in children ages two years and older. TA-TMA is a severe and often-fatal complication of hematopoietic stem cell transplantation in adults and children, driven by systemic endothelial injury triggered by conditioning regimens, immunosuppressants, infection, graft-versus-host disease, and other transplant-related factors. Activation of the lectin pathway of complement plays a central role in disease pathogenesis. YARTEMLEA selectively inhibits MASP-2, blocking pathway activation while preserving classical and alternative complement functions important for host defense. In TA-TMA, MASP-2 inhibition prevents lectin pathway-mediated cellular injury, including endothelial damage in small blood vessels, and thrombus formation.

Commercial distribution and sales of YARTEMLEA commenced in January 2026.

For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Overview: OurCommercial Product – YARTEMLEA”.

Sale of Zaltenibart / MASP-3

On November 25, 2025, we completed the Transaction pursuant to our APLA with Novo Nordisk for our candidate drug zaltenibart (formerly OMS906). Zaltenibart is a first-in-class, late-stage clinical humanized monoclonal antibody targeting MASP-3, the most upstream and key activator of the alternative pathway of the complement system. Zaltenibart has shown multiple potential advantages over other alternative pathway inhibitors in development and on the market.

At the closing of the Transaction, we received an upfront cash payment of $240.0 million. In addition, we are eligible to receive (i) up to $510.0 million in one-time milestone payments upon the first achievement by Novo Nordisk or its affiliates or sublicensees of each of the development and approval milestone events as set forth in the APLA and (ii) up to $1.3 billion in one-time milestone payments upon the first achievement by Novo Nordisk or its affiliates or sublicensees of certain sales-based milestone events as set forth in the APLA. We are also eligible under the APLA to receive tiered royalties on annual net sales of products at percentage rates ranging from high single digit to high teens, subject to reduction in certain circumstances, as set forth in the APLA. In total, we are eligible to receive up to an additional $1.8 billion in potential development and commercial milestones, plus tiered royalties on net sales.

Pursuant to the APLA, we sold and transferred, and Novo Nordisk purchased zaltenibart and certain related assets, and the parties agreed to grant and receive certain intellectual property licenses to facilitate the continued development and commercialization activities of both companies. We retain rights to our MASP-3 small-molecule program unrelated to zaltenibart, including the ability to develop and commercialize small-molecule MASP-3 inhibitors, across a range of therapeutic areas, including, but not limited to, ophthalmology, neurology, gastrointestinal disorders, dermatology, musculoskeletal diseases, and oncology. We also retain rights to our “grandfathered” MASP-3 antibodies, with temporal and indication restrictions on commercialization and for use in advancing our small-molecule therapeutics.

In accordance with the APLA, at the closing of the Transaction, Omeros and Novo Nordisk entered into the Transition Services Agreement pursuant to which we are providing certain transition services to Novo Nordisk to facilitate the transfer of the acquired assets and liabilities under the APLA and to provide for the continued operation of relevant studies and program activities during the applicable term. Subject to certain exceptions and limitations, Novo Nordisk reimburses us for costs and expenses we incur under the Transition Services Agreement, including third-party costs and expenses, costs associated with delivery of transition services by Omeros personnel on an hourly basis at rates specified in the Transition Services Agreement, and for our inventories of zaltenibart drug substance and product.

Other Development Programs

PDE7 Inhibitor Program

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 NIDA, 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. With NIDA funding, we successfully completed preclinical cocaine interaction/toxicology studies to assess safety of the OMS527 compound when co-administered with cocaine. FDA subsequently requested additional preclinical information prior to initiating the clinical in-patient study in cocaine users. Together with our collaborators at NIDA, we are scheduled to meet with FDA to discuss that request. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Other Development Programs: PDE7 Inhibitor Programs – OMS527”.

Preclinical Programs - OncotoX-AML

We continue to progress preclinical studies within our novel oncology program, which is focused on developing novel, proprietary large molecule therapeutics designed to selectively target and kill dividing cancer cells. We have completed selection of a drug development candidate, and IND-enabling studies are underway for this program, which we refer to as OncotoX-AML. AML, an aggressive and highly fatal bone marrow and blood cancer, is the lead indication for development. The effectiveness of current AML treatments, such as chemotherapeutics and antibody-drug conjugates, is limited by a number of factors, including high relapse rates and substantial side effects.

OncotoX-AML is an engineered biologic designed to selectively kill both AML blasts (abnormal myeloid cells) and relapse-related leukemia stem cells. Its unique mechanism of action is independent of myeloid cell genetic mutations, including TP53, NPM1, KMT2A, and FLT3, which are collectively found in approximately 90% of AML patients and are historically difficult to treat. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Other Development Programs: OncotoX-AML”.

Preclinical Programs - T-CAT

We are also advancing our T-CAT platform: a new class of recombinant antibodies intended for broad action against bacteria, fungi, viruses, and parasites. T-CAT is designed to harness complement activation to kill pathogens directly, which represents a novel approach to infectious disease treatment.

As preclinical animal data continue to accumulate across multiple pathogen classes and species, we believe that T-CAT demonstrates potential against MDROs. Effective MDRO therapies remain one of the most urgent and unmet needs in medicine, and we believe that T-CAT has the potential to address this need without contributing to drug resistance. For more information, see Part I, Item 1 in this Annual Report on Form 10-K under the heading “Other Development Programs: T-CAT - Infectious Disease”.

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 lens replacement (“IOL”) 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 OMIDRIA to Rayner pursuant to an Asset Purchase Agreement, dated December 1, 2021 (the “Asset Purchase Agreement”). In February 2023, we received a $200.0 million milestone payment from Rayner (the “Milestone Payment”), plus accrued interest, upon an event (the “Milestone Event”) that established separate payment for OMIDRIA for a continuous period of at least four years when furnished in an ambulatory surgery center (“ASC”) setting. The Asset Purchase Agreement also provides for the payment of royalties by Rayner based on Rayner's net sales of OMIDRIA for a term that extends for the life of the patents covering OMIDRIA in the relevant jurisdiction, the longest of which in the United States is currently into 2035. The applicable royalty rates are currently 30% in the United States and 15% outside the United States (“ex-U.S.”), subject to reduction upon certain events described in the Asset Purchase Agreement.

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 separate payment (i.e., becomes included in the packaged payment rate for the surgical procedure) under Medicare Part B, or in certain circumstances involving entry of generic competition for OMIDRIA, the U.S. base royalty rate would be further 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, we recorded an OMIDRIA contract royalty asset on our consolidated balance sheet. The results of OMIDRIA activities are classified as discontinued operations in our consolidated statements of operations and comprehensive loss and excluded from continuing operations for all periods presented. See Part II, Item 8, “Note 8 — Discontinued Operations – Sale of OMIDRIA” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

On September 30, 2022, we entered into a Royalty Purchase Agreement (the “Original Agreement”) with DRI Healthcare Acquisitions LP (“DRI”) under which we received $125.0 million in exchange for a portion of the royalties to which we were entitled from Rayner under the Asset Purchase Agreement on global net sales of OMIDRIA between September 1, 2022 and December 31, 2030, subject to certain annual caps on the royalty amounts payable to DRI. DRI was entitled under that arrangement to receive royalties on OMIDRIA net sales between September 1, 2022 and December 31, 2030, subject to certain annual caps.

On February 1, 2024, we sold an expanded interest in our future OMIDRIA royalties to DRI under an Amended and Restated Royalty Purchase Agreement (the “Amendment”) for which we received $115.5 million in cash consideration. We record the amounts payable to DRI as an OMIDRIA royalty obligation on our consolidated balance sheet. The Amendment eliminated the previously existing annual caps on royalty payments after January 1, 2024, and provides that DRI receives all royalties on U.S. net sales of OMIDRIA payable between January 1, 2024 and December 31, 2031. All royalties earned on OMIDRIA sales within the U.S. through December 31, 2031 are remitted by Rayner to an escrow account established by Omeros, from which payments are made to DRI.

We retain the rights to receive all royalties payable by Rayner on any net sales of OMIDRIA outside the U.S. as well as royalties on global net sales of OMIDRIA payable from and after December 31, 2031. To date, international royalties have not been significant.

DRI has no recourse to our assets other than its interest in OMIDRIA royalties. Interest expense on the OMIDRIA royalty obligation is recorded as a component of continuing operations. See Part II, Item 8, “Note 9 – OMIDRIA Royalty Obligation” to our Consolidated Financial Statements in this Annual Report on Form 10-K for additional information.

Debt Financing Transactions

Repayment at Maturity of 2023 Notes

On November 15, 2023, we extinguished $95.0 million of our 6.25% convertible senior notes (the “2023 Notes”) at par upon maturity.

Repurchase of 2026 Notes for Cash

In December 2023, we repurchased $9.1 million par value of our 2026 Notes on the open market at approximately 55% of par value, realizing a $4.1 million non-cash gain on extinguishment.

Exchange of 2026 Notes for Term Loan and Cash

On June 3, 2024, we, with certain subsidiaries, as guarantors, entered into a Credit and Guaranty Agreement (the “Credit Agreement”) with certain funds managed by Athyrium Capital Management, LP and certain funds managed by Highbridge Capital Management, LLC, as lenders (together with additional lenders from time to time, the “Lenders”) and Wilmington Savings Fund Society, FSB, as administrative agent and collateral agent. Along with borrowings of $67.1 million under the Credit Agreement (the “Term Loan”) and $21.7 million of cash on hand (for a total aggregate purchase price of $88.8 million), we repurchased from the lenders $118.1 million aggregate principal amount of our 2026 Notes. The $29.3 million difference between the $118.1 million aggregate principal amount of the 2026 Notes and the $88.8 million aggregate repurchase price was recorded as a premium (i.e., an increase) to the Term Loan on the Company’s consolidated balance sheet instead of being recognized as a gain on early extinguishment of debt as this was accounted for as a troubled debt restructuring.

Exchange of 2026 Notes for 2029 Notes and Equitization Transaction

On May 14, 2025, we completed the exchange (the “Convertible Note Exchange”) of $70.8 million of our 2026 Notes on a one-for-one basis for newly-issued 2029 Notes. The Convertible Note Exchange was conducted with a limited number of holders of the 2026 Notes pursuant to exchange agreements dated as of May 12, 2025. The 2029 Notes are convertible at the option of the holders into shares of common stock, cash or a combination thereof, as elected by the Company, at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date. Holders who convert their 2029 Notes after November 13, 2025 and prior to June 1, 2029 (except for any conversion in connection with a make-whole fundamental change) are entitled to an interest make-whole payment equal to the sum of the remaining scheduled payments of interest that would have been made had the 2029 Notes remained outstanding from their conversion date through the earlier of (i) the date that is 18 months following their conversion date, and (ii) June 15, 2029, the maturity date. The initial conversion rate for the 2029 Notes is equivalent to an initial conversion price of approximately $6.18 per share of our common stock. The conversion rate is subject to adjustment in certain circumstances.

The 2029 Notes include both a derivative for the interest make-whole feature and a derivative for the conversion feature available to holders allowing them to convert their notes to common stock, cash or a combination thereof. At each reporting date, we remeasure the embedded derivative instruments to fair market value. Increases or decreases in our stock price may materially affect the fair value of the derivative. The remeasurement of the derivative is presented in our consolidated statement of operations and comprehensive loss. At contract inception, we recorded a net $23.0 million embedded derivative as a component of our 2029 Notes. However, with the sale of OMS906 to Novo Nordisk and the announcement of FDA approval of TA-TMA, our stock price significantly increased. At December 31, 2025, the fair market value of our embedded derivative was $157.2 million. We marked-to-market the initial $23.0 million embedded derivative on the 2029 Notes and recorded a $134.2 million non-cash loss on remeasurement to our consolidated statement of operations and comprehensive loss.

On May 12, 2025, we entered into the note conversion agreements (each, a “Note Conversion Agreement”) with two holders of the 2026 Notes to convert $10.0 million aggregate principal amount of 2026 Notes into shares of our common stock in three tranches. We completed the conversion of the final tranche in September 2025, resulting in the issuance of an aggregate of 2,819,866 shares of our common stock to the two holders in exchange for the $10.0 million aggregate principal amount of 2026 Notes. We did not receive new cash proceeds in these transactions. We performed an assessment of the Convertible Note Exchange and Equitization Transaction and determined that these transactions were not a troubled debt restructuring and were a partial extinguishment of our 2026 Notes.

These transactions resulted in a net $3.0 million non-cash loss on extinguishment of the 2026 Notes due to (1) expensing of the unamortized debt issuance costs of the extinguished 2026 Notes, (2) recording the 2029 Notes to fair market value (i.e., at a discount) which we recorded both to our statement of operations and comprehensive loss and as debt on our balance sheet and (3) recording the fair market value of the share-settled liability upon settlement.

Repayment of Term Loan

On November 25, 2025, concurrent with the closing of the sale and licensing of zaltenibart (OMS906) to Novo Nordisk under the APLA, we were required under the terms of the Credit Agreement to repay in full the $67.1 million principal outstanding under the Term Loan along with a 5% prepayment premium. We recognized a net non-cash gain on extinguishment in the amount of $17.0 million which represents the de-recognition of $17.9 million in unamortized premium and debt issuance costs, derecognition of $2.6 million of embedded derivatives, partially offset by $3.5 million of prepayment premium and related transaction expenses.

Repayment of our obligations under the Credit Agreement resulted in the release in full of all liens and covenants thereunder including the covenant requiring us to maintain a minimum of $25.0 million in unrestricted cash, cash equivalents and short-term investments at all times.

Repayment at Maturity of Remaining 2026 Notes

On February 17, 2026, we repaid the remaining $17.1 million aggregate principal amount of outstanding 2026 Notes in full upon maturity.

See Part II, Item 8, “Note 7 – Debt” and “Note 12 – Shareholders Equity (Deficit)” to our Consolidated Financial Statements in this Annual Report on Form 10-K for additional information on any of these refinancing transactions.

Equity Financing Transactions

At the Market Sales Agreement

We have a sales agreement to sell shares of our common stock from time to time, through an “at the market” (“ATM”) equity offering program. During the year ended December 31, 2025, we sold 4.4 million shares of common stock pursuant to our ATM program, generating $19.0 million in net proceeds at an average price per share of $4.51. On November 14, 2025, the Company filed a shelf registration statement and prospectus supplement renewing the ATM program for an aggregate offering price up to $150.0 million, and as of the date of this annual report, we have $150.0 million in shares of our common stock available to sell under our ATM program.

Registered Direct Offering

On July 28, 2025, we issued and sold 5,365,853 shares of our common stock in a registered direct offering to entities managed by Polar Asset Management Partners at a price of $4.10 per share, representing a 14% premium to the closing price of our common stock on the date of the definitive agreement for the purchase of shares. We received $20.3 million in cash proceeds net of offering expenses.

Share Repurchase Programs

On November 9, 2023, the Board of Directors approved a share repurchase program under which we were permitted to repurchase from time to time up to $50.0 million of our common stock in the open market or through privately negotiated transactions. For the year ended December 31, 2023, we repurchased and retired 1.8 million shares of common stock at an average price of $2.54 per share for an aggregate purchase price of $4.7 million. During the first quarter of 2024, we repurchased and retired 3.2 million shares of common stock at an average of $3.71 per share for an aggregate purchase price of $11.9 million. The terms of the Credit Agreement prohibited us from repurchasing our common stock unless expressly agreed to by the Lenders. Consequently, the Board of Directors terminated the share repurchase program effective upon the execution of the Credit Agreement in May 2024. Repayment of our obligations under the Credit Agreement resulted in the release in full of all liens and covenants thereunder including the covenant prohibiting the Company from repurchasing its shares.

On November 29, 2025, the Board of Directors approved a new share repurchase program under which we are permitted to repurchase from time to time up to $100.0 million of our common stock in the open market or through privately negotiated transactions.

See Part II, Item 8, “Note 12 – Shareholders Equity (Deficit)” to our Consolidated Financial Statements in this Annual Report on Form 10-K for additional information on any of these refinancing transactions.

Financial Summary

As of December 31, 2025, we had cash, cash equivalents and short-term investments of $171.8 million. We had $87.9 million in aggregate principal amount of debt at December 31, 2025, reflecting a decrease of $77.1 million or 46.7% compared to our $164.9 million in aggregate principal amount of debt at December 31, 2024.

37

Table of Contents

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 product candidate, CROs, clinical trial sites, collaborators, licensors and consultants. Preclinical 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. Our accounting policy is to expense all manufacturing costs related to product candidates until regulatory approval is reasonably assured in either the U.S. or EU.

The following table illustrates our expenses associated with these activities:

Year Ended

Year Ended December 31,

(In thousands)

Research and development expenses:

Direct external expenses:

Clinical research and development:

Clinical research and development expenses decreased $33.5 million between 2025 and 2024. This change was primarily due to releasing $17.5 million in narsoplimab and $4.4 million of zaltenibart drug substance batches in the prior year. We experienced further reduction in spend of $5.5 million during the year related to the further close out of our IgA nephropathy program. In addition, we have also been in the process of closing out and winding down various studies as they relate to Phase 1 of OMS1029 and early Phase 2 studies of OMS906.

Clinical research and development expenses increased $0.5 million between 2024 and 2023. The change primarily relates to $16.1 million of TA-TMA drug manufacturing costs in anticipation of our BLA, mentioned above, and $2.1 million in zaltenibart clinical trials expense and associated costs to manufacture drug supply. These costs are partially offset by a $15.5 million reduction in IgA nephropathy expenses with the closing out of the program and a $2.2 million reduction in OMS1029 expenses primarily due to the completion of one of our single ascending dose studies.

Preclinical research and development expenses decreased $2.4 million in 2025 compared to 2024 primarily due to the completion of certain animal studies under our NIDA grant. In 2025, we also engaged in general cost cutting measures to conserve cash in anticipation of BLA approval of YARTEMLEA.

Preclinical research and development expenses increased $1.3 million in 2024 compared to 2023, primarily due to increased preclinical oncology research and cocaine addiction work related to our NIDA grant during 2024.

38

Table of Contents

Internal overhead and other expenses decreased $1.7 million for the year ended December 31, 2025 primarily due to reduced employee compensation costs and reduced overhead. Internal overhead and other expenses increased $3.5 million for the year ended December 31, 2024 primarily due to additional employee related costs and having received an employee retention tax credit in the prior year that was recorded as an offset to expense.

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

We expect our overall research and development costs in 2026 to be lower than in 2025. This anticipated decrease is primarily attributable to reduced clinical trial costs for zaltenibart as these program costs will be incurred by Novo Nordisk in connection with the APLA and the Transition Services Agreement, the absence of development milestone payments under our existing licensing agreement related to zaltenibart, and reduced spend on overall drug manufacturing. Our accounting policy is to expense all manufacturing costs related to product 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 product 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 product candidate as well as ongoing assessments of each program’s commercial potential. In addition, we cannot forecast with precision which product candidates, if any, may be subject to future collaborations, when such arrangements will be secured, if at all, and to what degree such arrangements would affect our development plans and capital requirements.

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

Selling, General and Administrative Expenses

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

Year Ended December 31,

(In thousands)

Selling, general and administrative expenses:

Total selling, general and administrative expenses $ 41,500 $ 47,430 $ 49,660

Selling, general and administrative expense, excluding stock-based compensation expense, decreased $4.2 million between 2025 and 2024 primarily due to reduced spend on third-party consultants and legal fees. In addition, we enacted cost containment measures in 2025 to conserve cash in anticipation of the launch of YARTEMLEA. The changes in stock-based compensation expense between the three covered years were due to the valuation and timing of vesting related to employee stock options.

We expect selling, general and administrative expenses in 2026 to increase compared to 2025, primarily reflecting costs associated with building our commercial infrastructure, including the hiring of a field sales force, marketing expenditures, and other commercial launch activities for YARTEMLEA.

39

Table of Contents

Gain on Sale of zaltenibart

Year Ended December 31,

(In thousands)

Gain on sale of zaltenibart $ 237,594 $ — $ —

On November 25, 2025, we closed the Transaction under the APLA with Novo Nordisk, pursuant to which Novo Nordisk received exclusive global rights in all indications to develop and commercialize zaltenibart and certain related compounds and products. Upon closing, we received net proceeds of $237.6 million comprising $240.0 million in upfront cash less $2.4 million in transaction fees.

Gain on Early Extinguishment of Term Debt, Net

Year Ended December 31,

(In thousands)

Gain on early extinguishment of term debt, net $ 17,035 $ — $ —

In November 2025, concurrent with the closing of the sale of zaltenibart to Novo Nordisk, the Company repaid in full the $67.1 million principal outstanding under the Term Loan. As a result, we recognized a net non-cash gain on extinguishment in the amount of $17.0 million which represents the de-recognition of $17.9 million in unamortized premium and debt issuance costs, derecognition of $2.6 million of embedded derivatives, offset by $3.5 million of prepayment premium and related transaction expenses.

Gain (Loss) on Early Extinguishment of 2026 Notes

Year Ended December 31,

(In thousands)

Gain (loss) on early extinguishment of 2026 Notes $ (2,968 ) $ — $ 4,112

In May 2025, we completed the Convertible Note Exchange and entered into the Equitization Transaction whereby we exchanged $70.8 million of aggregate principal amount of our 2026 Notes for the same aggregate principal amount of our new 2029 Notes and $10.0 million of aggregate principal amount of 2026 Notes for shares of our common stock. Our obligation to deliver these shares in three tranches was initially accounted for as a share-settled liability measured at fair value. We completed the conversion of the final tranche in September 2025, resulting in the issuance of an aggregate of 2,819,866 shares of our common stock to the two holders in exchange for the $10.0 million of aggregate principal amount of 2026 Notes. These transactions resulted in a net $3.0 million non-cash loss on extinguishment of our 2026 Notes due to (i) expensing of the unamortized debt issuance costs of the extinguished 2026 Notes, (ii) recording the 2029 Notes to fair market value (i.e., at a discount) which we recorded both to our consolidated statement of operations and comprehensive loss and as debt on our consolidated balance sheet and (iii) recording the fair market value of the share-settled liability upon settlement.

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.

Interest and Other Income

Year Ended December 31,

(In thousands)

Interest and other income principally includes interest earned on our investments, and to a lesser extent, sublease income and grant income from NIDA. The decreases over both years are primarily due to holding lower average cash and investment balances than in the preceding year.

We expect interest and other income in 2026 to be higher than 2025 primarily due to higher average cash and investment balances during 2026.

Interest Expense

Interest expense is comprised of contractual cash and accrued interest on our 2029 Notes, 2026 Notes, 2023 Notes and Term Loan. In addition, we record pass through interest on the OMIDRIA royalty obligation, non-cash interest comprised of remeasurement adjustments taken on our OMIDRIA royalty obligation and amortization of debt discount or premiums on our notes and term debt.

Interest expense, net of premiums, discounts, issuance costs and remeasurement adjustments is shown below:

Year Ended December 31,

(In thousands)

OMIDRIA royalty obligation

Non-cash remeasurement adjustment (33,435 ) (5,614 ) —

Amortization of debt discount and issuance costs 287 859 1,234

Term Loan

Contractual interest expense 8,021 5,525 —

Amortization of debt premium and issuance costs (5,578 ) (4,681 ) —

Interest expense on Term Loan 2,443 844 —

Contractual interest expense 4,220 — —

Amortization of debt discount and issuance costs 3,658 — —

Contractual interest expense — — 5,195

Amortization of debt discount and issuance costs — — 619

Interest on our OMIDRIA royalty obligation is calculated under the effective interest method and represents a portion of the royalties remitted by Rayner to our administrative agent, Wilmington Savings Fund Society, FSB, along with principal. Pass-through interest paid to DRI is offset by non-cash remeasurement adjustments taken to properly reflect the OMIDRIA royalty obligation for changes in probable cash flows on our future expected Rayner royalties.

Contractual interest expense is comprised of cash interest paid during the year and the net change in accrued interest. Amortization of debt discounts, premiums and issuance costs are reflected as non-cash interest expense. Debt discounts on the 2026 Notes and 2029 Notes are accretive whereas the premium on the Term Loan is deducted from contractual interest expense.

Interest expense decreased $25.6 million in 2025 compared to 2024. The decrease primarily relates to a $27.8 million change in non-cash remeasurement costs on the OMIDRIA royalty obligation to reflect a change in forecasted OMIDRIA cash flows from Rayner. Excluding any non-cash remeasurement adjustments of the DRI royalty obligation and any non-cash amortization of debt discount, premium, or issuance costs, contractual interest expense remains relatively unchanged from the prior year.

Interest expense decreased $6.2 million in 2024 compared to 2023 primarily due to the extinguishment of $95.0 million in aggregate principal amount of our 2023 Notes at maturity in November 2023 and partially repurchasing $127.2 million in aggregate principal amount of our 2026 Notes in December 2023 and June 2024 for a collective reduction in interest expense of $10.2 million. This decrease was partially offset by increased interest expense of $3.2 million related to our OMIDRIA royalty obligation as we added $115.5 million of principal upon sale in February 2024 to DRI of our remaining OMIDRIA U.S. royalty earnings through 2031. In addition, with the execution of the Credit Agreement, we incurred $0.8 million in effective interest on our Term Loan.

For further information see Part II, Item 8, “Note 7 – Debt” and “Note 9 – OMIDRIA Royalty Obligation” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

40

Table of Contents

Gain (Loss) on Change in Fair Value of Financial Instruments, Net

Year Ended December 31,

(In thousands)

Our embedded derivative comprises an interest make-whole and conversion option related to our 2029 Notes. As of December 31, 2025, the $136.7 million net loss on the embedded derivatives reflects marking to market the option of the 2029 Note holders to convert their notes into shares of common stock, cash or a combination thereof.

Swings in our stock price could significantly affect the valuation of the 2029 Note conversion derivative. In addition, a decrease in interest rates could increase the valuation of the derivative.

Income Tax Expense

Year Ended December 31,

(In thousands)

Income tax expense $ (2,012 ) $ (2,305 ) $ —

Income tax expense represents taxes payable to various state jurisdictions.

For further information see Part II, Item 8, “Note 14 – Income Taxes” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

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 classified as discontinued operations for all periods presented.

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

Year Ended December 31,

(In thousands)

Ex-US royalties 12 — —

Net income from discontinued operations, net of tax $ 1,458 $ 25,814 $ 57,107

41

Table of Contents

Interest on OMIDRIA contract royalty asset

During the years ended December 31, 2025, 2024 and 2023, we recorded $14.7 million, $16.9 million and $15.3 million, respectively, of income in discontinued operations representing interest income on the outstanding OMIDRIA contract royalty asset at an implied effective interest rate of 11.0%.

Remeasurement Adjustments

Periodically, but at least annually, we remeasure the OMIDRIA contract royalty asset when there is a greater probability of achieving materially higher or lower royalty earnings than previously expected. To measure the OMIDRIA contract royalty asset, we use 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. Remeasurement is impacted by any changes to the probability-weighting applied to the range of potential outcomes that could occur. For further discussion of discontinued operations, please refer to Part II, Item 8, “Note 8 – 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.

Income Tax Expense

For the years ended December 31, 2025, 2024 and 2023, we recorded state income tax expense of $0.6 million, $0.3 million and $0.5 million, respectively, in discontinued operations.

42

Table of Contents

Financial Condition- Liquidity and Capital Resources

The Transaction with Novo Nordisk, which closed on November 25, 2025, provided us with $240.0 million in upfront cash. Under the Credit Agreement, the Company used a portion of the proceeds from the Transaction to repay the $67.1 million outstanding principal on the Term Loan, along with $3.5 million in related prepayment premiums and transaction expenses. Repayment of our obligations under the Credit Agreement resulted in the release in full of all liens and covenants thereunder, including the covenant requiring us to maintain a minimum of $25.0 million in unrestricted cash, cash equivalents and short-term investments at all times.

As of December 31, 2025, we had cash, cash equivalents and short-term investments of $171.8 million. We had $87.9 million in aggregate principal amount of debt at December 31, 2025, reflecting a decrease of $77.1 million, or 46.7%, compared to $164.9 million in aggregate principal amount of debt at December 31, 2024. Subsequent to year end, we repaid at maturity the remaining $17.1 million aggregate principal amount of our 2026 Notes in February 2026.

We expect that we will be able to fund more than 12 months of operations from the remaining proceeds from our current cash, cash equivalents, and short-term investments, along with funds we expect to receive from commercial sales of YARTEMLEA from the date of issuance of the financial statements.

Should it be necessary or determined to be strategically advantageous, we also could pursue public and private offerings of our equity securities, debt transactions or restructurings, future royalty sales, or other strategic transactions, which may include licensing or selling a portion or all of one or more of our existing technologies. In addition, 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 of up to $150.0 million.

43

Table of Contents

Cash Flow Data

Year Ended December 31,

(In thousands)

Selected cash flow data

Cash provided by (used in):

Operating Activities. Net cash used in operating activities decreased by $32.7 million for the year ended December 31, 2025 compared to the same period in 2024. The change was primarily due to a decrease in net loss of $153.5 million and $112.8 million of change in non-cash charges, partially offset by a $237.6 million gain on sale of zaltenibart to Novo Nordisk.

Net cash used in operating activities for the year ended December 31, 2024 decreased by $223.5 million compared to the same period in 2023. This change was primarily due to collecting the $200.0 million Milestone Payment from Rayner in February 2023 and a $15.5 million decrease in accounts payable and accrued expenses in the current year.

Investing Activities. Net cash provided by investing activities for the year ended December 31, 2025 increased $82.3 million as compared to the same period in 2024 primarily due to proceeds received from the sale of zaltenibart in the fourth quarter.

Net cash provided by investing activities for the year ended December 31, 2024 increased $54.8 million as compared to the same period in 2023. Significant initial investment purchases during the periods were the investment of the $200.0 million Milestone Payment we received from Rayner in February 2023 and the $115.5 million we received from DRI in February 2024 related to the sale of future OMIDRIA royalties.

Financing Activities. Net cash used in financing activities increased $105.1 million during 2025 compared to the prior year primarily due to (i) receiving $115.5 million in cash from DRI for the sale of future OMIDRIA royalties in February 2024 and (ii) repayment of the Term Loan of $67.1 million along with payments totaling $3.5 million related to prepayment premiums and transaction related fees. These changes were partially offset by net proceeds received from a registered direct offering of $20.3 million, net issuances of common stock through our ATM of $19.0 million and an increase in proceeds from the exercise of stock options of $7.1 million in the current year. Additionally, we used $21.7 million to repurchase our 2026 Notes and $11.9 million to repurchase common stock.

Net cash provided by financing activities increased $169.0 million during 2024 compared to the prior year. The increase was primarily due to receiving $115.5 million in cash from DRI related to the sale of future OMIDRIA royalties in February 2024 and extinguishing $95.0 million of par value on our 2023 Notes at maturity in August 2023. This was partially offset by increased payments to DRI of $17.6 million in 2024 related to the OMIDRIA royalty obligation, an additional $16.9 million paid to repurchase our 2026 Notes and increased common stock repurchases of $7.2 million.

Contractual Obligations and Commitments

Operating and Finance Leases

We have operating leases related to our office and laboratory space. The initial term of the leases is through November 2027, and we have two options to extend the lease term, each by five years. As of December 31, 2025, the remaining aggregate non-cancelable rent payable under the initial term of the lease, excluding common area maintenance and related operating expenses, was $12.7 million.

We have finance leases for certain laboratory and office equipment that have lease terms expiring through October 2029. As of December 31, 2025, the remaining aggregate non-cancellable finance lease payable was $1.3 million.

44

Table of Contents

Debt

For more information regarding the repayment of our 2023 Notes, 2026 Notes and Term Loan, as well as issuance of our 2029 Notes, see Part II, Item 8, “Note 7 - Debt”.

OMIDRIA Royalty Obligation

For more information regarding the OMIDRIA Royalty Obligation, see Part II, Item 8, “Note 9 - OMIDRIA Royalty Obligation”.

Goods& Services

We have certain non-cancellable obligations under other agreements for the acquisitions of goods and services associated with the manufacturing of our product candidates, which contain firm commitments. As of December 31, 2025, our aggregate firm commitments were $2.6 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. For information regarding agreements that include these royalty and milestone payment obligations, see Part II, Item 8, “Note 11 - 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:

● OMIDRIA royalties and contract asset accounting;

● OMIDRIA royalty obligation accounting;

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

● valuation of embedded derivative.

45

Table of Contents

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.

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 at an implied effective interest rate of 11%. The contract royalty asset excludes any revenue which potentially may be reversed in the event of an over estimation.

We receive monthly royalty reports of 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 consolidated statement of operations and comprehensive income and as an OMIDRIA contract royalty asset on our consolidated balance sheet.

Upon achieving the Milestone Event in February 2023, the royalty rate applicable to U.S. net sales of OMIDRIA was reduced from 50% to 30%. The 30% royalty rate continues until the expiration or termination of the last issued and unexpired U.S. patent, which we expect to occur no earlier than 2035. We currently earn a royalty rate of 15% on net ex-U.S. sales. Royalties earned are recorded as a reduction to the OMIDRIA contract royalty asset.

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 $12.2 million change in value of the OMIDRIA contract royalty asset, resulting in a potential OMIDRIA contract royalty asset valued within the range of $109.6 million to $134.0 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 is remeasured periodically using the expected value approach based on actual results and future expectations. The royalties earned and any remeasurement adjustments are recorded in discontinued operations.

OMIDRIA Royalty Obligations

The sale of any portion of our OMIDRIA royalty receipts is treated as a liability on our consolidated balance sheet, 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.

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. Any remeasurement adjustment is recognized as a component of interest expense in net loss from continuing operations. Our estimate of cash flows from future royalties is derived from the contract royalty asset accounting described above.

46

Table of Contents

Debt Issuances and Repayment

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 first evaluated as to whether they qualify as a troubled debt restructuring (“TDR”) under ASC Topic 470-60, Debt - Troubled Debt Restructuring by Debtors (“ASC 470-60”). ASC 470-60 requires debt modifications to be evaluated if (1) the borrower is experiencing financial difficulty, and (2) the lender grants the borrower a concession. If both conditions are met under TDR accounting, we would record as the carrying value of the new debt any repurchased old debt less any cash paid. No gain on restructuring is recognized unless the carrying value of the new debt exceeds the undiscounted cash flows of the new debt. Any cancellation of debt income is amortized over the term of the new debt. We determined that the Term Loan qualified as a TDR. Therefore, we amortized as debt premium the cancellation of debt income from the partial repurchase of the 2026 Notes against the Term Loan.

If a TDR is determined to not have occurred, we evaluate the modification in accordance with ASC Topic 470-50-40, Debt - Modifications and Extinguishments, which requires modification of debt instruments to be evaluated to assess whether the modifications are considered “substantial”. In instances where our future cash flows change more than 10%, we record our debt at fair value based on factors available to us for similar borrowings and use the extinguishment accounting method.

We refer to debt as being “extinguished” if the debt is repaid due to mandatory repayment features in the contract or upon maturity of the debt.

In November 2023, we repaid our 2023 Notes at maturity. This did not result in any gain or loss on our consolidated statement of operations and comprehensive loss as the related debt discount and issuance costs were already fully amortized.

The partial repurchase of the 2026 Notes in 2023 was deemed to be a modification whereby we were able to recognize a $4.1 million gain on debt extinguishment.

In May 2025, the Convertible Note Exchange and Equitization Transactions were treated as a partial extinguishment of the 2026 Notes under the debt accounting guidance. These transactions resulted in a net $3.0 million non-cash loss on extinguishment of our 2026 Notes due to (1) expensing of the unamortized debt issuance costs of the extinguished 2026 Notes, (2) recording the 2029 Notes to fair market value (i.e., at a discount) which we recorded both to our consolidated statement of operations and comprehensive loss and as debt on our consolidated balance sheet and (3) recording the fair market value of the share-settled liability upon settlement.

In November 2025, the sale of zaltenibart to Novo Nordisk triggered the mandatory and full repayment of all outstanding principal under the Term Loan. As a result, we recognized a net non-cash gain on extinguishment in the amount of $17.0 million which represents the de-recognition of $17.9 million in unamortized premium and debt issuance costs, derecognition of $2.6 million of embedded derivatives, offset by $3.5 million of prepayment premium and related transaction expenses.

In February 2026, we repaid the remaining outstanding aggregate principal amount of our 2026 Notes in full upon maturity.

Please refer to Part II, Item 8, “Note 7 - Debt” to our Consolidated Financial Statements in this Annual Report on Form 10-K.

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, debt instruments and embedded derivatives.

Cash, Cash Equivalents and Short-Term Investments

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, 2025, 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 money market funds in our investment portfolio are not leveraged and are classified as available-for-sale. 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, we are not exposed to significant loss due to changes in interest rates.

Convertible Notes, Term Debtand Embedded Derivatives

As of December 31, 2025 and December 31, 2024, we had fixed-rate borrowings from our 2026 Notes and 2029 Notes. We record all of our fixed-rate borrowings at amortized cost and, therefore, do not experience any risk for changes in interest rates. However, we include embedded derivatives along with our debt in our reporting of our 2029 Notes and Term Loan in our consolidated balance sheets. The repayment of our Term Loan in November 2025 resulted in the de-recognition of the associated embedded derivative as of December 31, 2025. The derivatives on our 2029 Notes are marked to fair value every reporting period. The fair value inputs to the 2029 Notes’ derivative valuation include stock price, unsecuritized discount rate, risk-free rate, volatility, and term. Swings in our stock price could significantly affect the valuation of the 2029 Note conversion derivative. In addition, a decrease in interest rates could increase the valuation of the derivative. As of December 31, 2025, a 20% decrease or increase in our stock price results in an approximate $39.0 million change in the fair value of the 2029 Notes embedded derivative within the range of $119.0 million to $197.0 million.

47

Table of Contents

ITEM8.FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Index to Consolidated Financial Statements

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 42) 49

Consolidated Balance Sheets 50

Consolidated Statements of Operations and Comprehensive Loss 51

Consolidated Statement of Shareholders’ Equity (Deficit) 52

Consolidated Statements of Cash Flows 53

Notes to Consolidated Financial Statements 54

48

Table of Contents

Report of Independent Registered Public Accounting Firm

To the Shareholders and the Board of Directors of Omeros Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Omeros Corporation (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss,shareholders' equity (deficit) and cash flows for each of the three years in the period ended December 31, 2025, 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, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion