What changed in this filing

/stocks — the workspaceLOADING

Item 1. Financial Statements

2026-05-13 compared with 2025-11-13 · 581 added, 634 removed, 463 unchanged (72% of the section changed)

3 unchanged sentences

(In thousands, except share and per share data)

September 30,

Current assets:

13 unchanged sentences

OMIDRIA royalty obligation

Convertible senior notes, net

2026 Notes, net

Lease liabilities

1 unchanged sentence

OMIDRIA royalty obligation, non-current

Convertible senior notes, non-current, net

Term debt, non-current, net

2029 Notes, non-current, net

2029 Notes embedded derivative, non-current

Lease liabilities, non-current

3 unchanged sentences

Preferred stock, par value $ 0.01 per share, 20,000,000 shares authorized;

none issued and outstanding at September 30, 2025 and December 31, 2024.

Common stock, par value $ 0.01 per share, 150,000,000 shares authorized at September 30, 2025 and December 31, 2024;

70,073,622 and 58,044,465 shares issued and outstanding at September 30, 2025 and December 31, 2024, respectively.

none issued and outstanding at March 31, 2026 and December 31, 2025.

Common stock, par value $ 0.01 per share, 150,000,000 shares authorized at March 31, 2026 and December 31, 2025;

71,998,632 and 71,670,791 shares issued and outstanding at March 31, 2026 and December 31, 2025, respectively.

Additional paid-in capital

4 unchanged sentences

OMEROS CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(In thousands, except share and per share data)

Three Months Ended

Nine Months Ended

September 30,

Product sales, net

Costs and expenses:

Cost of product sales

Research and development

2 unchanged sentences

Loss from operations

Interest expense, net of remeasurement adjustments and other

Interest and other income

Loss on early extinguishment of 2026 Notes

Net loss on change in fair value of financial instruments

Net loss from continuing operations

Net income (loss) from discontinued operations, net of tax

Interest expense, net of remeasurement adjustments and other

Net gain (loss) on change in fair value of financial instruments

Income (loss) from continuing operations before income tax expense

Income tax expense

Net income (loss) from continuing operations

Net income from discontinued operations, net of tax

Net income (loss)

Basic net income (loss) per share:

Net loss from continuing operations

Net income (loss) from discontinued operations

Weighted-average shares used to compute basic net income (loss) per share

Net income (loss) from continuing operations

Net income from discontinued operations

Net income (loss)

Diluted net income (loss) per share:

Net income (loss) from continuing operations

Net income from discontinued operations

Net income (loss)

Weighted-average shares used in per share computation:

See accompanying Notes to Condensed Consolidated Financial Statements

4 unchanged sentences

Issuance of common stock upon exercise of stock options

Repurchases of common stock

Net share settlement of equity awards

Stock-based compensation expense

Balance at March 31, 2026

Issuance of common stock - at-the-market equity offering facility, net

Issuance of common stock - 2026 Notes equitization

Issuance of common stock upon exercise of stock options

Stock-based compensation expense

Balance at June 30, 2025

Issuance of common stock - registered direct offering

Issuance of common stock - at-the-market equity offering facility, net

Issuance of common stock - 2026 Notes equitization

Issuance of common stock upon exercise of stock options

Stock-based compensation expense

Balance at September 30, 2025

Balance at January 1, 2025

Issuance of common stock upon exercise of stock options

Repurchases of common stock

Stock-based compensation expense

Balance at March 31, 2025

Issuance of common stock upon exercise of stock options

Stock-based compensation expense

Balance at June 30, 2024

Issuance of common stock upon exercise of stock options

Stock-based compensation expense

Balance at September 30, 2024

See accompanying Notes to Condensed Consolidated Financial Statements

2 unchanged sentences

(In thousands)

Nine Months Ended September 30,

Three Months Ended March 31,

Operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Net income (loss)

Adjustments to reconcile net income (loss) to net cash used in operating activities:

Stock-based compensation expense

Loss on early extinguishment of 2026 Notes

Amortization of discount and issuance costs on convertible notes

Remeasurement on fair value of financial instruments

Amortization of discount and issuance costs on 2026 Notes and 2029 Notes

Depreciation and amortization

Remeasurement on OMIDRIA royalty obligation

Remeasurement on fair value of financial instruments

Non-cash interest remeasurement on OMIDRIA royalty obligation

Non-cash interest on OMIDRIA contract royalty asset

1 unchanged sentence

Amortization of premium and issuance costs on term debt

Accretion on U.S.

government treasury bills, net

Changes in operating assets and liabilities:

9 unchanged sentences

Financing activities:

Proceeds from registered direct offering, net

Proceeds from issuance of common stock from the ATM facility, net

Proceeds upon exercise of stock options

Exercise of stock options

Repayment of 2026 Notes

Principal payments on OMIDRIA royalty obligation

Payment of debt issuance costs related to 2029 Notes

Payments on finance lease obligations

Proceeds from sale of future royalties

Cash paid to repurchase 2026 convertible senior notes

Repurchases of common stock

Net cash provided by financing activities

Net decrease in cash and cash equivalents

Net share settlement of equity awards

Payments on finance lease obligations

Net cash used in financing activities

Net increase (decrease) in cash and cash equivalents

Cash and cash equivalents at beginning of period

1 unchanged sentence

Supplemental cash flow information

Exchange of 2026 Notes for 2029 Notes

Exchange of 2026 Notes for common stock

Cash paid for interest

Cash paid (received) for income taxes, net

Equipment acquired under finance lease

Cash paid for income taxes, net

See accompanying Notes to Condensed Consolidated Financial Statements

2 unchanged sentences

Note 1 — Organization and Basis of Presentation

Omeros Corporation (“Omeros,” the “Company” or “we”) is a clinical-stage biopharmaceutical company committed to discovering, developing, and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting immunologic diseases, including complement-mediated diseases and cancers related to dysfunction of the immune system, as well as addictive and compulsive disorders.

Omeros Corporation (“Omeros,” the “Company” or “we”) is 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.

Our clinical-stage development programs include:

zaltenibart, also known as OMS906, our antibody targeting mannan-binding lectin-associated serine protease-3 (“MASP-3”), the key activator of the alternative pathway of complement;

narsoplimab, our antibody targeting mannan-binding lectin-associated serine protease 2 (“MASP-2”), the effector enzyme of the lectin pathway of complement;

1 unchanged sentence

and OMS527, our phosphodiesterase 7 (“PDE7”) inhibitor program.

On October 10, 2025, we entered into an APLA with Novo Nordisk Health Care AG (“Novo Nordisk”), pursuant to which Novo Nordisk will receive exclusive global rights in all indications to develop and commercialize zaltenibart and certain related monoclonal antibodies and antigen-binding fragments (collectively, the “Compounds”), and related pharmaceutical products (“Products”) upon the Closing as defined below.

Under the APLA, we agreed to sell and transfer, and Novo Nordisk agreed to purchase and assume, certain assets and liabilities related to the Compounds and Products, and the parties agreed to grant and receive certain intellectual property licenses, as further described below (the “Transaction”).

Subject to the satisfaction or waiver of the closing conditions contained in the APLA, the Transaction is expected to close in the fourth quarter of 2025.

Pursuant to the terms and subject to the conditions of the APLA, we are eligible to receive $ 340.0 million in upfront and near-term milestone payments, of which $ 240.0 million is to be received by us at the closing of the Transaction (the “Closing”).

Beyond the $ 340.0 million, we can receive (i) an additional $ 410.0 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.

During 2025, we entered into an Asset Purchase and License Agreement (“APLA”) with Novo Nordisk Health Care AG (“Novo Nordisk”) for exclusive global rights in all indications to develop and commercialize zaltenibart, also known as OMS906, our lead antibody targeting mannan-binding lectin-associated serine protease-3 (“MASP-3”), the key activator of the alternative pathway of complement.

We retain rights to our MASP-3 small-molecule program, 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 develop our “grandfathered” MASP-3 antibodies, with temporal and indication restrictions on commercialization, and for use in advancing our small-molecule therapeutics.

FDA Approval of YARTEMLEA ®

On December 23, 2025, FDA approved YARTEMLEA ® (narsoplimab-wuug) for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (“TA-TMA”).

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 pathway 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.

YARTEMLEA is the first and only approved inhibitor of the lectin pathway of complement.

YARTEMLEA is approved for the treatment of TA-TMA in adults and in children ages two years and older.

Commercial distribution and sales of YARTEMLEA commenced in January 2026.

A marketing authorization application (“MAA”) for YARTEMLEA in TA-TMA has been submitted to the European Medicines Agency (“EMA”) and is being reviewed under EMA’s centralized review procedure, which allows review of a single marketing authorization application.

If the MAA is approved, it would authorize the product to be marketed in all European Union (“EU”) member states and European Economic Area countries.

The European Commission has granted narsoplimab designation as an orphan medicinal product for treatment in hematopoietic stem cell transplantation.

For commercialization of YARTEMLEA outside the U.S., we are evaluating potential partnerships, including broad ex-U.S.

and regional collaborations.

Sale of Zaltenibart

On November 25, 2025, we completed a transaction (the “Transaction”) pursuant to the APLA between Omeros and Novo Nordisk, dated October 10, 2025, in which Novo Nordisk received exclusive global rights in all indications to develop and commercialize our lead investigational MASP-3 inhibitor, zaltenibart (formerly OMS906), and certain related compounds and products.

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.

The Closing is subject to the satisfaction or waiver of certain customary closing conditions, including (i) the absence of any law, order, or governmental proceeding that prohibits or makes illegal the consummation of the Transaction, (ii) the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, (iii) the accuracy of each party’s representations and warranties contained in the APLA (subject to customary materiality and other qualifiers), (iv) each party’s performance and compliance with its covenants contained in the APLA, (v) the absence of a material adverse effect, and (vi) delivery of certain closing deliverables.

We have substantially completed two Phase 2 clinical trials evaluating zaltenibart in paroxysmal nocturnal hemoglobinuria (“PNH”) and have an ongoing open label extension study to assess the long-term efficacy and safety of zaltenibart in PNH patients who have completed either of the two Phase 2 clinical trials.

We also have a small, ongoing Phase 2 study evaluating zaltenibart in complement 3 glomerulopathy (“C3G”), a rare and debilitating renal disease driven by complement dysregulation.

We began initiating clinical trial sites in our Phase 3 program for zaltenibart in PNH during the first quarter of 2025;

however, based on considerations of capital availability and the anticipated ramp up in spending on those trials, we have determined temporarily to pause our Phase 3 clinical development program for zaltenibart in this indication in order to prioritize the use of our available capital to other programs.

Our ongoing and planned clinical programs for zaltenibart will be transitioned to Novo Nordisk following the closing of the Transaction throughout which we will provide certain transition services to Novo Nordisk.

Our pipeline of clinical-stage complement-targeted therapeutic candidates also includes narsoplimab in TA-TMA, which, upon approval, will be marketed as YARTEMLEA.

We successfully completed a pivotal clinical trial for narsoplimab in TA-TMA and previously submitted to FDA a BLA seeking marketing approval for narsoplimab in this indication.

In October 2021, FDA issued a complete response letter (“CRL”) with respect to the original BLA and indicated that additional information would be needed to support regulatory approval.

We appealed FDA’s decision to issue the CRL through a formal dispute resolution process that concluded in late 2022.

Although our appeal was denied, the decision identified potential paths for resubmission of the BLA, including paths based on comparison of survival data from the completed pivotal trial to a historical control group.

Based on the recommendations included in the appeal decision and on subsequent interactions with FDA’s review division, we developed a statistical analysis plan to assess data from our pivotal clinical trial, existing data from a historical control population available from an external source, and data from the narsoplimab expanded access program.

In March 2025, we resubmitted to FDA the BLA seeking regulatory approval for narsoplimab in TA-TMA.

The resubmission was accepted for review by FDA as a class 2 resubmission and, pursuant to the Prescription Drug User Fee Act (“PDUFA”), was assigned a target action date for the FDA decision of September 25, 2025.

Following the submission of information in response to an information request from FDA, FDA informed us that the PDUFA date has been extended to December 26, 2025.

We expect that FDA will meet this PDUFA date.

All analyses requested by FDA as part of its review have been consistent with and have provided statistically significant support of narsoplimab’s benefit demonstrated in the analyses submitted as part of the BLA resubmission.

In June 2025, we submitted a MAA for narsoplimab for the treatment of TA-TMA in the European Union.

The EMA completed validation of the narsoplimab MAA, which confirms that the submission is accepted and starts the formal review process by EMA’s Committee for Medicinal Products for Human Use.

We expect an opinion on the MAA in mid-2026.

As with any BLA or MAA, there can be no guarantee that FDA or the EMA will complete their respective reviews within a given timeframe, or that our BLA or MAA will ultimately be approved.

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 a transition services agreement (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

Our lectin pathway program also includes OMS1029, our long-acting antibody targeting MASP-2.

2 unchanged sentences

OMS1029 has been well tolerated to date with no safety concerns identified.

Several indications for potential Phase 2 clinical development of OMS1029 have been evaluated/selected and may be pursued pending the availability and allocation of capital.

OMS1029 drug product and placebo have been manufactured and stored for future use.

Available quantities are expected to be sufficient to support a Phase 2 clinical 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 the National Institute on Drug Abuse (“NIDA”), part of the National Institutes of Health, to develop, at NIDA’s request, our lead orally administered PDE7 inhibitor compound for the treatment of cocaine use disorder.

NIDA awarded the grant to us for a total of $ 6.2 million over three years, of which we expensed $ 2.1 million and have claimed and received $ 1.6 million of funding to date.

The grant is intended to support preclinical cocaine interaction/toxicology studies to assess safety of the therapeutic candidate in the presence of concomitant cocaine administration, as well as an in-patient, placebo-controlled clinical study evaluating the safety and efficacy of OMS527 in adult cocaine users who receive concurrent intravenous cocaine.

The preclinical studies, designed with NIDA toxicologists, have been successfully completed with no safety findings and provide drug-interaction safety data in support of the planned in-patient human study of OMS527 in cocaine users.

FDA has requested that we provide additional preclinical information prior to initiating the clinical in-patient study in cocaine users, which we are targeting for the second half of 2026.

We are working to finalize selection of an indication and initiate Phase 2 clinical development of OMS1029.

In addition, we have selected a development candidate for our MASP-2 small molecule program, which is advancing to Investigational New Drug (“IND”)-enabling studies targeting once-daily oral administration.

In April 2023, we were awarded a grant from the National Institute on Drug Abuse (“NIDA”), to develop an orally administered PDE7 inhibitor compound for the treatment of cocaine use disorder.

NIDA awarded the grant to us for a total of $ 6.24 million over three years, of which we have claimed and received $ 2.3 million of funding to date.

FDA subsequently requested additional nonclinical information prior to initiating the clinical in-patient study.

Following a meeting with FDA to discuss that request, we are working with FDA to streamline the path to initiate the in-patient clinical trial, which is targeted for initiation by year-end 2026.

We also have various programs in preclinical research and development.

Liquidity and Capital Resources

As of September 30, 2025, we had cash, cash equivalents, and short-term investments of $ 36.1 million.

For the nine months ended September 30, 2025, our cash used in operations was $ 76.3 million and included a net loss for the nine months ended September 30, 2025 of $ 89.8 million.

Pursuant to a covenant under that certain Credit and Guarantee Agreement, dated June 3, 2024 (the “Credit Agreement”), among the Company, the various lenders party thereto, and Wilmington Savings Fund Society, FSB, as Administrative Agent and Collateral Agent, we must maintain $ 25.0 million of unrestricted cash, cash equivalents and short-term investments at all times.

We have maintained a balance of unrestricted cash, cash equivalents, and short-term investments greater than $ 25.0 million and at no time during the nine months ended September 30, 2025 or through the date of issuance of these condensed consolidated financial statements have we been in violation of any of our debt covenants.

In recent years, Omeros has incurred net losses from continuing operations and negative cash flows from operations.

The conditions described above, exclusive of any potential future activities, including the anticipated closing of the Transaction with Novo Nordisk or receipt of any related potential milestone payments and/or near-term regulatory approval of narsoplimab, raise substantial doubt with respect to our ability to meet our obligations through one year from the issuance of the Company’s condensed consolidated financial statements.

Our ability to continue as a going concern will require us to do one or several of the following:

generate positive cash flow from operations, enter into strategic alliances, obtain additional financing, and/or sell assets.

The Transaction with Novo Nordisk is expected to close in the fourth quarter of 2025 and would provide us with $ 240.0 million in upfront cash.

A portion of the $240.0 million upfront payment would be applied to the repayment of all outstanding obligations under the Credit Agreement.

The repayment would relate to the $ 67.1 million outstanding term debt (the “Term Loan”) under the Credit Agreement, along with related prepayment premiums, expenses and accrued and unpaid interest.

Repayment of our obligations under the Credit Agreement would result 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.

(See “Note 6 — Debt” for further details).

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 (collectively, “Polar”) 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.

Further, we have a sales agreement pursuant to an at-the-market (“ATM”) equity offering facility through which we may, from time to time, offer and sell shares of our common stock for proceeds of up to an aggregate amount of $ 150.0 million.

During the three and nine months ended September 30, 2025, we received $ 9.0 million and $ 15.3 million, respectively, of net proceeds from the sale of our common stock through the ATM facility and have received $ 3.6 million subsequent to September 30, 2025.

(See “Note 11 – Stockholders Deficit”).

If the ATM facility is needed but inaccessible, we are not able to close the Transaction, or we are not able to obtain debt and/or royalty-related financing and/or partnering funding in connection with a near-term regulatory approval of narsoplimab, it would have a significant negative impact on our financial condition.

For purposes of determining available capital resources, any future royalty and/or milestone receipts are excluded.

We have taken steps to manage our operating expenses and reduce our projected cash requirements by delaying clinical trials and reducing selected research and development efforts.

Should it be necessary, we may determine to further reduce or delay these or other aspects of our operations and/or implement restructuring activities.

Should the need arise to raise further capital for our operations, we may pursue public and private offerings of our equity securities, 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.

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.

Acute myeloid leukemia (“AML”), an aggressive and highly fatal bone marrow and blood cancer, is the lead indication for development.

We are also advancing our targeted complement activating therapy (“T-CAT”) platform:

a new class of recombinant antibodies intended for broad action against pathogens, including 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.

Our initial focus is on T-CAT’s potential against multidrug-resistant organisms.

Basis of Presentation

4 unchanged sentences

generally accepted accounting principles (“GAAP”).

These financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2024, from which the December 31, 2024, condensed consolidated balance sheet has been derived.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes.

Significant items subject to such estimates include the OMIDRIA contract royalty asset valuation, the OMIDRIA royalty obligation valuation and our valuation of embedded derivatives.

Significant items subject to such estimates include revenue recognition and the valuations of the OMIDRIA contract royalty asset, the OMIDRIA royalty obligation, and the embedded derivatives associated with our debt.

We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances;

5 unchanged sentences

The Company’s CODM is our Chief Executive Officer.

For the three and nine months ended September 30, 2025, the Company has identified one operating and reporting segment.

The CODM reviews net loss and expenses reported on the condensed consolidated statement of operations and comprehensive income (loss).

The measurement of segment assets is reported on the balance sheet as total consolidated assets.

For the three months ended March 31, 2026, the Company has identified one operating and reporting segment.

The CODM reviews net income (loss) and expenses reported on the condensed consolidated statement of operations and comprehensive income (loss).

The measurement of segment assets is reported on the condensed consolidated balance sheet as total consolidated assets.

All long-lived assets are held in the U.S.

Our segment net income (loss) aligns with our condensed consolidated statement of operations and comprehensive income (loss).

2024 Term Loan and Repurchase of 2026 Notes

In June 2024, we performed an assessment of the Credit Agreement and determined that it met the criteria to be accounted for as a troubled debt restructuring.

As a result, the $ 29.3 million difference between the $ 118.1 million aggregate principal amount of the 2026 Notes (as defined below) repurchased by the Company and the $ 88.8 million aggregate repurchase price (consisting of the $ 67.1 million Term Loan and $ 21.7 million cash on hand) was recorded as a premium (i.e.

an increase) to the term debt recorded on our condensed consolidated balance sheet instead of being recognized as a gain on early extinguishment of debt.

We amortize the premium as both a reduction of term debt in the condensed consolidated balance sheet and interest expense in the condensed consolidated statement of operations and comprehensive loss over the duration of the Term Loan.

Exchange of 2026 Notes for 2029 Notes and Common Stock

On May 14, 2025, we completed the exchange (the “Convertible Note Exchange”) of $ 70.8 million of our existing 5.25 % convertible senior notes due on February 15, 2026 (the “2026 Notes”) on a one-for-one basis for newly-issued convertible senior notes maturing on June 15, 2029 (the “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.

On May 12, 2025, we entered into 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 (the “Equitization Transaction”) in three tranches.

Our obligation to deliver shares in three tranches was initially accounted for as a share-settled liability measured at fair value.

As of September 30, 2025, we completed the conversion of all three tranches, resulting in the issuance of an aggregate of 2,819,866 shares of our common stock to the two holders.

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.

The Convertible Note Exchange and the Equitization Transaction reduced the aggregate principal balance of our 2026 Notes from $ 97.9 million to $ 17.1 million.

(For further details, see “Note 6 – Debt”).

Embedded Derivatives

We account for convertible instruments in accordance with ASC 470-20, Debt with Conversion and Other Option s, when we determine that embedded conversion features do not require bifurcation from the host instrument.

We account for convertible instruments (when we have determined that the embedded conversion options should be bifurcated from their host instruments) in accordance with ASC 815 – Derivative and Hedge Accounting (“ASC 815”).

Under ASC 815, proceeds received upon the issuance of the hybrid contract are allocated between the fair value of the notes and the fair value of the derivative.

The derivative is subsequently marked-to-market at each reporting date based on current fair value, with the changes in fair value reported in the condensed consolidated statements of operations and comprehensive loss.

The embedded derivative on our 2029 Notes represents the conversion feature and interest make-whole feature available to holders of the 2029 Notes allowing them to convert the notes into common stock.

The embedded derivative on our Term Loan represents the prepayment feature and the probability of the Company entering into a material transaction prompting us to prepay the Term Loan.

(For further details, see “Note 6 – Debt”).

Revenue Recognition

When we enter into a customer contract, we perform the following five steps:

(i) identify the contract with a customer;

(ii) identify the performance obligations in the contract;

(iii) determine the transaction price;

(iv) allocate the transaction price to the performance obligations in the contract;

and (v) recognize revenue when (or as) we satisfy a performance obligation.

Product Sales, Net

We generally recognize revenue from product sales when the product is delivered to our wholesalers and title to the product is transferred, upon which we have satisfied our performance obligations.

Fulfillment activities by the wholesalers are not considered to be a separate performance obligation.

Product revenue is recorded net of variable consideration, including wholesaler distribution fees, chargebacks, returns and discounts.

We estimate variable consideration using the expected value approach.

This estimate is based on several factors, including:

historical return rates, expiration date by product and estimated levels of inventory in the wholesale channel.

Since there is often a timing lag between the product sale and the settlement of accruals relating to these programs, our net product revenue may incorporate revisions of accruals for several periods.

We include such estimates in the transaction price only to the extent that it is probable that a significant reversal of revenue will not occur when the uncertainty associated with the variable consideration is subsequently resolved.

Given the limited commercialization history of YARTEMLEA, our estimates of variable consideration require judgment and are subject to change as additional data becomes available.

We recognize adjustments to net product revenue in the period in which changes in estimates become known.

Chargebacks represent discounts provided to eligible covered entities under government programs, including the 340B Drug Pricing Program (“340B”) and the Medicaid Drug Rebate Program (“Medicaid”).

In addition, we are subject to pricing obligations under our Federal Supply Schedule agreement with the U.S.

government (the “FSS Agreement”), which establishes maximum prices for sales to certain federal agencies and may give rise to additional discounts and rebates.

Chargebacks are recorded as a reduction of gross product revenue at the time of sale.

Reserves for chargebacks are generally recorded as reductions of accounts receivable, while reserves for Medicaid rebates and patient co-pay assistance, if applicable, are recorded as accrued liabilities.

Chargeback estimates are based on statutory pricing requirements applicable to the 340B program and expected utilization by covered entities.

Given the limited commercial history of our recently launched product, these estimates require significant judgment, including assumptions related to future utilization patterns and channel inventory.

Estimates are reassessed at each reporting period and adjusted as necessary based on actual experience, changes in 340B utilization, and other relevant factors.

In addition to 340B chargebacks and Medicaid rebates, we maintain programs that may result in additional variable consideration, including a patient co-pay assistance program.

There was no activity under the Medicaid and co-pay assistance program during the three months ended March 31, 2026, and, accordingly, no material related reductions to gross product revenue were recorded.

We will continue to evaluate these programs as utilization evolves and will recognize the related reductions to revenue in the period in which they occur.

Distribution Fees and Return Allowances

We pay distribution fees to wholesalers for services they perform on our behalf.

These fees are calculated based on the wholesalers’ average acquisition cost of purchases of YARTEMLEA, exclusive of any chargebacks.

We estimate these amounts at the time of sale to the wholesaler and record them as a reduction in product sales in the same period the related revenue is recognized.

We allow for the return of product up to 12 months past its expiration date or for product that is damaged.

In estimating product returns, we take into consideration our return experience to date, the remaining shelf-life of product we have previously sold, inventory in the wholesale channel, and our expectation that product is typically not held by health care providers based on the frequency of their reorders.

There were no product returns in the three months ended March 31, 2026.

Due to the ordering patterns associated with transplant centers and the extended shelf life of YARTEMLEA, returns are expected to be limited;

however, our estimates may change as commercial experience matures.

Cost of Product Sales

Cost of product sales includes third-party manufacturing, royalties based on net product sales, and other costs directly related to the production and distribution of YARTEMLEA.

We expensed as research and development expense all costs associated with the manufacture of YARTEMLEA produced prior to FDA approval.

As a result, the cost basis of inventory available for sale at the time of commercialization was minimal, and cost of product sales is correspondingly low during the initial period following launch.

Following FDA approval, we capitalize direct manufacturing costs as inventory and recognize these amounts in cost of product sales when the related inventory is sold.

Accordingly, cost of product sales and gross margin during the initial periods following commercialization may not be indicative of future periods as we begin capitalizing and expensing post‑approval manufacturing costs.

Research and Development

Research and development expenses are comprised primarily of contracted research and development activities, clinical trial study and manufacturing costs prior to approval;

consulting services;

contract milestones;

materials and supplies;

costs for personnel, including salaries, benefits, and stock-based compensation;

depreciation;

an allocation of our occupancy costs;

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

Advance payments for goods or services that will be used for future research and development activities are deferred and then recognized as an expense as the related goods are delivered or the services are performed.

All other research and development costs are expensed as incurred.

Selling, General and Administrative

Selling, general and administrative expenses are comprised primarily of marketing expenses;

professional and legal services;

patent costs;

and salaries, benefits, and stock-based compensation costs for marketing and other personnel not directly engaged in research and development.

Additionally, selling, general and administrative expenses include depreciation, an allocation of our occupancy costs, and other general corporate expenses.

Advertising costs are expensed as incurred.

Stock-Based Compensation

Stock-based compensation expense is recognized for all share-based payments, including grants of stock option awards and restricted stock units based on estimated fair values.

The fair value of our stock is calculated using the Black-Scholes option-pricing model, which requires assumptions around volatility, forfeiture rates, risk-free interest rate and expected term.

Compensation expense is recognized over the requisite service periods, which is generally the vesting period, using the straight-line method.

Forfeiture expense is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates.

Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax basis.

Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled.

We recognize the effect of income tax positions only if those positions are more likely than not to be sustained upon an examination by the relevant taxing authority.

A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized.

Asset Sale Transactions

The Company evaluates transactions involving the sale of our compounds, products or drug programs to determine whether such arrangements represent a sale of a business or a sale of a nonfinancial asset.

Transactions that do not meet the definition of a business are accounted for as the sale of a nonfinancial asset under Accounting Standards Codification (“ASC”) 610‑20, Other Income — Gains and Losses from the Derecognition of Nonfinancial Assets .

Upon transfer of control of the compound, product or drug program asset to a counterparty, the Company recognizes consideration received.

Any excess of consideration over the carrying value of the asset sold is recognized as a gain in the condensed consolidated statements of operations.

Potential Milestone Income

The APLA with Novo Nordisk includes variable consideration in the form of milestone payments that are contingent upon the achievement of specified development, regulatory or commercialization events.

The Company applies the variable consideration and constraint guidance in ASC 606, Revenue from Contracts with Customers , by analogy.

At contract inception and throughout the term of the arrangement, the Company assesses whether the achievement of each milestone is probable and estimates variable consideration using the most likely amount method.

Contingent milestone payments are excluded from the transaction price until the related milestone is achieved and it is probable that a significant reversal of cumulative revenue recognized will not occur.

Amounts are included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved.

The Company re-evaluates the transaction price at each reporting period, including the estimated variable consideration and the application of the constraint, to reflect changes in circumstances.

Factors considered in these evaluations include the clinical or technical complexity of the milestone, the stage of development, and the risk of regulatory approval.

Because of the risk that products in development will not receive regulatory approval, we generally do not recognize any contingent payments that would be due to us until regulatory approval.

Discontinued Operations

2 unchanged sentences

Planned or completed business dispositions are presented as discontinued operations when all the criteria described above are met.

We determined that the zaltenibart Transaction with Novo Nordisk did not meet the above criteria.

As such, we recorded the gain on sale of zaltenibart in Other Income in our condensed consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

On December 23, 2021, we closed on an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Rayner Surgical Inc.

(“Rayner”) for the sale of our commercial product OMIDRIA which we recorded as an OMIDRIA contract asset on our condensed consolidated balance sheet.

As a result of the divestiture, the results of OMIDRIA activities are classified as discontinued operations in our condensed consolidated statements of operations and comprehensive loss and excluded from continuing operations for all periods presented.

(“Rayner”) for the sale of our commercial product OMIDRIA, which we record as an OMIDRIA contract asset on our condensed consolidated balance sheet.

As a result of the divestiture, the results of OMIDRIA activities are classified as discontinued operations in our condensed consolidated statement of operations and comprehensive income (loss) and excluded from continuing operations for all periods presented.

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.

1 unchanged sentence

The sale of OMIDRIA qualified as an asset sale under GAAP.

To measure the OMIDRIA contract royalty asset, we use the expected value approach, which represents the sum of the discounted, probability-weighted royalty payments we would receive using a range of potential outcomes, provided it is probable that a significant reversal in the amount of cumulative income recognized will not occur.

Royalties earned are recorded as a reduction to the OMIDRIA contract royalty asset.

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.

royalties received from Rayner through December 31, 2031 are remitted by Rayner to an escrow account established by Omeros, from which payments are made to DRI Healthcare Acquisition LP (“DRI”) and are entirely pass-through in nature to the Company.

2 unchanged sentences

The OMIDRIA contract royalty asset is re-measured quarterly using the expected value approach, which incorporates actual results and future expectations.

(See “Note 7 — Discontinued Operations – Sale of OMIDRIA”).

(For further details see “Note 7 — Discontinued Operations —Sale of OMIDRIA”).

OMIDRIA Royalty Obligation

We have sold to DRI our future U.S.

based OMIDRIA royalty receipts through December 31, 2031, which we recorded as an OMIDRIA royalty obligation on our condensed consolidated balance sheet.

The OMIDRIA royalty obligation is valued based on our estimates of future royalties from Rayner.

Interest expense is calculated at an implied effective interest rate of 10.27 % and represents a component of the total pass-through payments to DRI from Rayner.

To the extent our estimates of future royalties differ materially from previous estimates, we will adjust the carrying amount of the OMIDRIA royalty obligation to reflect the present value of the revised estimated cash flows from Rayner utilizing the cumulative catch-up method.

This is reflected as a remeasurement adjustment recognized as non-cash interest expense.

Pass-through interest, remitted through an administrative agent by Rayner to DRI, and non-cash interest on remeasurements are recorded to continuing operations to arrive at interest (income) or expense on the OMIDRIA royalty obligation.

(See “Note 8 — OMIDRIA Royalty Obligation”).

We expense inventory costs related to product candidates as research and development expenses until regulatory approval is reasonably assured in the U.S.

or the European Union (“EU”).

Once approval is reasonably assured, costs, including amounts related to third-party manufacturing, transportation, and internal labor and overhead, will be capitalized.

On September 30, 2022, we sold to DRI a portion of our future OMIDRIA royalty receipts for a purchase price of $ 125.0 million and recorded an OMIDRIA Royalty Obligation for the same amount.

On February 1, 2024, DRI purchased our remaining U.S.

OMIDRIA royalty receipts through December 31, 2031 for $ 115.5 million in cash under an Amended and Restated Royalty Purchase Agreement (the “Amendment”).

The Amendment eliminated the previously existing annual caps on royalty payments and provides that DRI receives all royalties on U.S.

net sales of OMIDRIA payable between January 1, 2024 and December 31, 2031.

We accounted for the Amendment as a modification of our existing debt from DRI.

The OMIDRIA royalty obligation is valued based on our estimates of future OMIDRIA royalties and is amortized through December 31, 2031.

To the extent our estimates of future royalties differ materially from the previous estimates, we will adjust for future OMIDRIA royalties to the present value of the revised estimated cash flows, discounted at the implied effective interest rate of 10.27 % utilizing the cumulative catch-up method.

We record interest expense as a component within continuing operations.

Any such remeasurement adjustment is recognized as non-cash interest expense within continuing operations (see “Note 8 - OMIDRIA Royalty Obligation”).

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

Cash and cash equivalents include highly liquid instruments with a maturity of three months or less on the date of purchase, which can be easily converted into cash without a significant impact on their value.

Short-term investment securities are classified as held-to-maturity, except for money market funds, which are classified as available-for-sale.

Investments classified as available-for-sale are measured at fair value.

Investments classified as held-to-maturity are carried at cost.

Amortization, accretion, interest, and dividends, realized gains and losses and declines in value judged to be other-than-temporary are included within other income.

The cost of securities sold is based on the specific-identification method.

Investments with maturities of less than one year, or those for which management intends to use the investments to fund current operations, are included in current assets.

We evaluate whether an investment is other-than-temporarily impaired based on the specific facts and circumstances.

Factors that are considered in determining whether an other-than-temporary decline in value has occurred include:

the market value of the security in relation to its cost basis;

the financial condition of the investee;

and the intent and ability to retain the investment for a sufficient period of time to allow for recovery in the market value of the investment.

Restricted investments held in money-market funds include security deposits on our office lease.

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

Receivables relates primarily to sales of YARTEMLEA to wholesalers and include estimated chargebacks and product returns that are expected to be settled through reductions in receivables, royalties receivable from Rayner on sales of OMIDRIA and receivables from Novo Nordisk for work performed under the Transition Services Agreement.

Considering the nature of our receivables, including that trade receivables are primarily due from a limited number of customers, we recorded no material allowance for expected credit losses as of March 31, 2026 and December 31, 2025, respectively.

Property and Equipment, Net

Property and equipment are stated at cost, and depreciation is calculated using the straight-line method over the estimated useful life of the assets, which is generally between three and ten years.

Expenditures for repairs and maintenance are expensed as incurred.

Inventory is stated at the lower of cost or market determined on a specific identification basis in a manner that approximates the first-in, first-out (FIFO) method.

Costs include amounts related to third-party manufacturing, transportation and internal labor and overhead.

Capitalization of costs as inventory begins when regulatory approval of the product candidate is reasonably assured in the U.S.

We expense inventory costs related to product candidates as research and development expenses prior to receiving regulatory approval in the applicable territory.

Inventory is reduced to net realizable value for excess and obsolete inventories based on forecasted demand.

The Company accounts for its convertible debt at carrying value, net of applicable discounts, premiums and debt issuance costs.

These instruments are recognized as a single liability on the condensed consolidated balance sheets unless specific features require treatment under separate accounting guidance.

Debt issuance costs, which include legal, accounting, and underwriting fees directly attributable to the financing, are presented as a direct deduction from the carrying amount of the convertible debt.

These costs and any original issue discounts are amortized to interest expense over the contractual term of the debt using the effective interest method.

The Company classifies convertible debt as long-term or current based on the remaining maturity and the status of the conversion features at the balance sheet date.

If the holders of the debt possess the right to convert the instrument into shares of the Company’s common stock within one year of the balance sheet date, or if the debt is otherwise callable, the respectivecarrying value of the converted debt is classified as current.

The Company performs a periodic evaluation of the conversion conditions to ensure proper classification and to determine if the debt should be measured based on its settlement value.

Upon conversion, the carrying value of the debt, including any unamortized costs, is typically reclassified to stockholders’ equity, and no gain or loss is recognized unless the conversion includes an inducement.

In February 2026, we repaid in full the remaining $ 17.1 million principal balance outstanding on our 2026 Notes upon maturity.

On November 25, 2025, concurrent with the closing of the sale of zaltenibart to Novo Nordisk under the APLA, the Company repaid in full the $ 67.1 million principal balance outstanding under the Company’s Credit and Guarantee Agreement with certain funds managed by Athyrium Capital Management, LP and certain funds managed by Highbridge Capital Management, LLC, as lenders (the “Term Loan”).

As of March 31, 2026, the Company has outstanding one series of convertible notes, which mature on June 15, 2029 (the “2029 Notes”) with an outstanding principal balance of $ 70.8 million.

(For further details, see “Note 6 – Debt”).

Embedded Derivatives

Under ASC 815, proceeds received upon the issuance of the hybrid contract are allocated between the fair value of the notes and the fair value of the derivative.

The embedded derivative on our Term Loan was eliminated upon repayment on November 25, 2025.

(For further details, see “Note 4 – Fair Value Measurements” and “Note 6 – Debt”).

Right-of-Use Assets and Related Lease Liabilities

5 unchanged sentences

We account for leases with initial terms of 12 months or less as an operating expense.

government enacted the One Big Beautiful Bill Act (“OBBBA”) on July 4, 2025, which includes new IRC 174A.

This section allows for immediate expensing of domestic research and development expenditures for tax years beginning after December 31, 2024, reversing the prior requirement under the 2017 Tax Cuts and Jobs Act which capitalized domestic research and development costs over five years.

The OBBBA also provides transition rules for domestic research and development expenditures for costs capitalized between December 31, 2021 and January 1, 2025.

The Company is in the process of assessing the potential impact of this legislative change on our financial statement disclosures.

Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled.

We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination by the relevant taxing authority.

A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized.

Common Stock Repurchases

We have repurchased shares of our common stock from time to time under authorization made by our Board of Directors.

Under applicable Washington State law, repurchased shares are retired and not presented separately as treasury stock in the condensed consolidated financial statements.

Financial Instruments and Concentrations of Credit Risk

1 unchanged sentence

The fair value of short-term investments is based on quoted market prices.

Financial instruments that are potentially subject to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments, receivables, convertible notes, and term debt.

Convertible notes and term debt are measured at fair market value at issuance.

Associated embedded derivatives of the convertible notes and term debt are remeasured quarterly to fair value.

At times, our cash and cash equivalents balance held at financial institutions may exceed the federally insured limits.

Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments and receivables.

Cash and cash equivalents are held by financial institutions and are federally insured up to certain limits.

At times, our cash and cash equivalents balance held at a financial institution may exceed the federally insured limits.

To limit the credit risk, we invest our excess cash in high-quality securities such as money market mutual funds, certificates of deposit and U.S.

1 unchanged sentence

Recent Accounting Pronouncements

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40):

Disaggregation of Income Statement Expense , requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis.

ASU 2024-03 is effective for annual years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted.

The Company is currently evaluating the impact on its financial statement disclosures.

In November 2024, the FASB issued ASU 2024-04, Debt - Debt with Conversion and Other Options (Subtopic 470-20):

Induced Conversions of Convertible Debt Instruments , which provides clarification on the accounting treatment of convertible debt settlements that occur under terms differing from those of the original instrument.

The amendments specify that if the settlement is considered an induced conversion, an entity must recognize an inducement expense at the offer acceptance date.

Conversely, if the settlement is treated as a debt extinguishment, an entity must recognize a gain or loss at the extinguishment date.

This ASU is effective for all entities for annual years beginning after December 15, 2025, including interim periods within those years, with early adoption permitted.

The Company is in the process of assessing the potential impact of this ASU on its debt accounting policies.

Note 3 — Net Loss Per Share

In November 2024, the Financial Accounting Standards Board (“FASB”) issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40):

Disaggregation of Income Statement Expense (“ASU 2024-03”), requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis.

ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted.

The Company is currently evaluating the impact of adopting ASU 2024-03 on its consolidated financial statements.

In December 2025, the FASB issued ASU 2025-10, Government Grants (Topic 832):

Accounting for Government Grants Received by Business Entities (“ASU 2025-10”), which establishes authoritative guidance on the recognition, measurement, presentation, and disclosure of government grants.

Under ASU 2025-10, government grants are recognized when it is probable that the entity will both comply with the conditions of the grant and the grant will be received.

The ASU provides specific accounting models for grants related to assets and grants related to income, including options to recognize government grants as deferred income or as a reduction of the asset’s cost basis.

The ASU also requires enhanced disclosures regarding the nature of government grants, significant terms and conditions, accounting policies applied, and amounts recognized in the financial statements.

ASU 2025-10 is effective for fiscal years beginning after December 15, 2028, including interim periods within those fiscal years, with early adoption permitted.

The Company is currently evaluating the impact of adopting ASU 2025-10 on its consolidated financial statements.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270):

Narrow-Scope Improvements (“ASU 2025-11”), which clarifies the guidance in Topic 270 to improve the consistency of interim financial reporting.

The ASU provides a comprehensive list of required interim disclosures and introduces a disclosure principle requiring entities to disclose events since the end of the last annual reporting period that have a material impact on the entity.

ASU 2025-11 is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years, with early adoption permitted.

The Company is currently evaluating the impact of adopting ASU 2025-11 on its consolidated financial statements.

Note 3 — Net Income (Loss) Per Share

Basic net income (loss) per share (“Basic EPS”) is computed by dividing net income (loss) by the weighted average number of common shares outstanding during the period.

Diluted net income (loss) per share (“Diluted EPS”) is computed by dividing net income (loss) by the weighted average number of common shares and potentially dilutive common shares outstanding during the period.

Our potential dilutive securities include common shares related to our stock options which are calculated using the treasury stock method.

Our potential dilutive securities related to our convertible senior notes are calculated using the if-converted method.

In periods where we have a net loss from continuing operations but overall net income, we do not compute Diluted EPS because the effect would be anti-dilutive.

When there is a net loss, potentially dilutive securities, like stock options, warrants, or convertible debt, are typically excluded from the diluted net loss per share calculation.

Diluted net loss per share (“Diluted EPS”) is computed by dividing net income (loss) by the weighted average number of common shares and potentially dilutive common shares outstanding during the period.

Our potentially dilutive securities include common shares related to our stock options calculated using the treasury stock method and convertible senior notes calculated using the if-converted method.

In periods where we have a net loss from continuing operations but overall net income, we do not compute Diluted EPS because the effect would be antidilutive.

When there is a net loss, potentially dilutive securities, like stock options or convertible debt, are typically excluded from the diluted net loss per share calculation.

Potentially dilutive securities excluded from Diluted EPS are calculated based on a weighted average of days in the quarter from when the respective transactions occurred and are shown as follows:

Three Months Ended

Nine Months Ended

September 30,

2029 Notes convertible to common stock (1)

2 unchanged sentences

Total potentially dilutive shares excluded from net loss per share

On May 14, 2025, we exchanged $ 70.8 million aggregate principal amount of our 2026 Notes for 2029 Notes on a one-for-one basis in the Convertible Note Exchange and recorded a reduction of an additional $ 10.0 million aggregate principal amount of our 2026 Notes to be equitized pursuant to the Equitization Transaction.

On May 14, 2025, we completed the exchange of $ 70.8 million aggregate principal amount of our 2026 Notes for 2029 Notes on a one-for-one basis in the Convertible Note Exchange (as defined below) and recorded a reduction of an additional $ 10.0 million aggregate principal amount of our 2026 Notes to be equitized in three tranches by September 2025.

The 2029 Notes are subject to a conversion arrangement that potentially increases the dilutive effect of conversion as described in “Note 6 — Debt.”

The 2026 Notes are subject to a capped call arrangement that potentially reduces the dilutive effect of conversion as described in “Note 6 — Debt.” Any potential impact of the capped call arrangement is excluded from this table.

On June 3, 2024, we repurchased $ 118.1 million of our 2026 Notes, reducing any effect of the dilution related to these notes.

(For further details refer to “Note 6 — Debt”).

The 2026 Notes were subject to a capped call arrangement that potentially reduced the dilutive effect of conversion as described in “Note 6 — Debt.” Any potential impact from the capped call arrangement is excluded from this table.

The remaining outstanding 2026 Notes were fully repaid at maturity on February 15, 2026.

Note 4 — Fair-Value Measurements

7 unchanged sentences

Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy.

There have been no transfers of assets or liabilities between fair value measurement classifications during the nine months ended September 30, 2025.

There have been no transfers of assets or liabilities between fair value measurement classifications during the three months ended March 31, 2026.

Our fair value hierarchy for our financial assets and liabilities measured at fair value on a recurring basis are as follows:

September 30, 2025

March 31, 2026

(In thousands)

1 unchanged sentence

Certificate of deposit classified as non-current restricted investments

Short-term investment:

Short-term investments:

Money-market funds

Call and put options derivative (1)

2029 Note conversion option derivative

Total Liabilities

While the Term Loan is recorded as a liability, the embedded call and put options that have been identified as requiring bifurcation are recognized as a net embedded derivative liability reflected as a component of the Term Loan on the balance sheet.

December 31, 2025

4 unchanged sentences

Money-market funds

Call and put options derivative (1)

2029 Note conversion option derivative

Total Liabilities

While the Term Loan is recorded as a liability, the embedded call and put options that have been identified as requiring bifurcation are recognized as a net embedded derivative asset reflected as a component of the Term Loan on the balance sheet.

Cash held in demand deposit accounts of $ 2.4 million and $ 3.4 million is excluded from our fair-value hierarchy disclosure as of September 30, 2025 and December 31, 2024, respectively.

Cash held in demand deposit accounts of $ 1.9 million and $ 9.7 million is excluded from our fair-value hierarchy disclosure as of March 31, 2026 and December 31, 2025, respectively.

The carrying amounts reported in the accompanying condensed consolidated balance sheets for receivables, accounts payable and accrued liabilities, and other current monetary assets and liabilities approximate fair value.

All of our investments, which are classified as Level 1 assets, are short-term and held in our name.

All our investments, which are classified as Level 1 assets, are short-term and held in our name.

Money market funds are classified as available-for-sale.

Our share-settled liability and embedded derivatives are classified as Level 3 assets and liabilities.

Our embedded derivatives are grouped with their related host contract as a net liability on our condensed consolidated balance sheet.

Our embedded derivative is classified as a Level 3 liability.

(For further details see “Note 6 – Debt”).

The fair value of our embedded derivatives were determined using both the Lattice and Discounted Cash Flow models with the following key assumptions:

September 30,

Term Loan derivative

Interest comprised of:

SOFR benchmark rate

Securitized discount rate

Yield volatility

Probability weighted term (in years)

Changes in valuation assumptions could have a significant impact on our Term Loan derivative.

The Company can provide no assurance that changes in yield would not be significant in the future.

September 30,

The fair value of our embedded derivative was determined using the Discounted Cash Flow model with the following key assumptions:

2029 Note conversion option derivative

8 unchanged sentences

An increase in our stock price volatility could increase the valuation of the 2029 Note conversion option derivative, whereas an increase in interest rates could decrease the valuation of the 2029 Note conversion option derivative.

The following table sets forth a summary of changes in the fair value of Level 3 liabilities for the nine months ended September 30, 2025:

(For further details see “Note 6 — Debt”).

The following table sets forth the change in the fair value of the 2029 Note conversion option derivative for the three months ended March 31, 2026:

Balance as of

September 30,

Change in Fair Value

(In thousands)

Share-settled liability

Call and put options derivative

2029 Note conversion option derivative

Total Liabilities

Note 5 — Certain Balance Sheet Accounts

1 unchanged sentence

The OMIDRIA contract royalty asset consists of the following:

September 30,

(In thousands)

3 unchanged sentences

See “Note 7 — Discontinued Operations – Sale of OMIDRIA” for discussion regarding the estimated fair value of our OMIDRIA contract royalty asset.

OMIDRIA Royalty Obligation

The OMIDRIA contract royalty obligation consists of the following:

(In thousands)

Short-term OMIDRIA royalty obligation

Long-term OMIDRIA royalty obligation

Total OMIDRIA royalty obligation

See “Note 8 — OMIDRIA Royalty Obligation” for further details.

Receivables consist of the following:

September 30,

(In thousands)

Trade receivables, net

OMIDRIA royalty receivables

Novo Nordisk receivable

Other receivables

Total receivables

OMIDRIA royalty receivables represents approximately two months of royalty earnings from Rayner.

Trade receivables represents sales of YARTEMLEA to wholesalers and include reductions for estimated chargebacks.

OMIDRIA royalty receivables represent approximately two months of royalty earnings from Rayner.

royalties received from Rayner are remitted by Rayner to an escrow account, established by Omeros, from which payments are made on our behalf to DRI.

2 unchanged sentences

Property and equipment, net consists of the following:

September 30,

(In thousands)

5 unchanged sentences

Total property and equipment, net

For the three months ended September 30, 2025 and 2024, depreciation and amortization expense was $ 0.2 million, for each period.

For the nine months ended September 30, 2025 and 2024, depreciation and amortization expense was $ 0.7 million and $ 0.6 million, respectively.

For the three months ended March 31, 2026 and 2025, depreciation and amortization expense was $ 0.2 million and $ 0.3 million, respectively.

Accrued Expenses

Accrued expenses consist of the following:

September 30,

(In thousands)

1 unchanged sentence

Clinical trials

Interest payable

Contract research and development

Deferred income

Consulting and professional fees

Income taxes payable

Interest payable

Other accrued expenses

Total accrued expenses

Deferred income as of March 31, 2026 and December 31, 2025 primarily related to billings to Novo Nordisk under the Transition Services Agreement.

Note 6 — Debt

Convertible senior notes, net, and term debt balances are comprised of the following:

September 30,

Convertible senior notes, net, balances are comprised of the following:

(In thousands)

Convertible senior notes, net maturing on June 15, 2029 (2029 Notes)

Term debt, net maturing on June 3, 2028 (Term Loan)

Convertible senior notes, net maturing on February 15, 2026 (2026 Notes)

Exchange of 2026 Notes for 2029 Notes and Common Stock

On May 14, 2025, we completed the exchange of $ 70.4 million of net carrying value of our 2026 Notes on a one-for-one basis for newly issued convertible senior notes maturing on June 15, 2029 which had a fair market value of $ 73.5 million.

The $ 70.4 million net carrying value of our 2026 Notes includes $ 70.8 million of aggregate principal amount less $ 0.4 million of issuance costs.

Including the Equitization Transaction, this exchange resulted in a net $ 3.0 million loss on extinguishment which we recorded to our statement of operations and comprehensive loss.

The Convertible Note Exchange was conducted with a limited number of holders of the 2026 Notes pursuant to exchange agreements dated May 12, 2025 (each, an “Exchange Agreement”).

2029 Notes, net maturing on June 15, 2029

2026 Notes, net matured on February 13, 2026

2029 Notes embedded derivative reported at fair value

Exchange of 2026 Notes for 2029 Notes

On May 14, 2025, we completed the exchange (the “Convertible Note Exchange”) of $ 70.8 million in aggregate principal amount 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 were issued pursuant to an Indenture, dated as of August 14, 2020 (the “Base Indenture”), between the Company and Computershare Trust Company, National Association, as successor to Wells Fargo Bank, National Association, as trustee (the “Trustee”), as supplemented by a Second Supplemental Indenture, dated as of May 14, 2025 (the “Second Supplemental Indenture”), between the Company and the Trustee (the Base Indenture, as amended and supplemented by the Second Supplemental Indenture, the “Indenture”).

The 2029 Notes will mature on June 15, 2029 unless earlier converted, redeemed or repurchased in accordance with their terms prior to such date.

Interest on the 2029 Notes is payable semi-annually in arrears at a rate of 9.50 % per annum on each June 15 and December 15, beginning on December 15, 2025.

Due to the discount amortization on the 2029 Notes, interest expense is currently being recognized at an implied effective interest rate of 1.82 %.

The 2029 Notes are convertible at the option of the holder into shares of common stock, cash or a combination thereof, as elected by us, at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date.

Embedded Derivative

The embedded derivative on the 2029 Notes includes 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.

At contract inception, we recorded a net $ 23.0 million embedded derivative as a component of our 2029 Notes to the condensed consolidated balance sheet.

At March 31, 2026 and December 31, 2025, the fair market value of our embedded derivative was $ 84.0 million and $ 157.2 million, respectively.

We recorded a $ 73.1 million non-cash gain on the remeasurement of the embedded derivative in our condensed consolidated statement of operations and comprehensive income for the three months ended March 31, 2026.

Increases or decreases in our stock price may materially affect the value of the derivative, and are shown as gains or losses in our condensed consolidated statement of operations and comprehensive income (loss).

Interest Make Whole Feature

Holders who convert their 2029 Notes 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.

Conversion Feature

The 2029 Notes are convertible at the option of the holder into shares of common stock, cash or a combination thereof at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date.

The Company elects whether the conversion occurs in common stock, cash or a combination thereof.

The conversion rate is 161.81 shares of our common stock per $ 1,000 of note principal (equivalent to an initial conversion price of approximately $ 6.18 per share of common stock), which equals approximately 11.5 million shares issuable upon conversion.

The conversion rate is subject to adjustment in certain circumstances as described in the Indenture.

Holders who convert their 2029 Notes from, and including, November 14, 2025 to, but excluding, June 1, 2029 (except for any conversion in connection with a make-whole fundamental change) will also be entitled to an interest make-whole payment equal to the sum of the remaining scheduled payments of interest that would have been made on the 2029 Notes to be converted had such notes remained outstanding from the conversion date through the earlier of (i) the date that is 18 months following the conversion date and (ii) the maturity date.

We recorded a $ 23.0 million initial embedded derivative as a component of our 2029 Notes which represents the conversion feature available to holders of the 2029 Notes allowing them to convert the notes into common stock.

At September 30, 2025, we marked-to-market the initial $ 23.0 million embedded derivative on the 2029 Notes to $ 22.2 million, recording a net $ 0.8 million gain on remeasurement to our condensed consolidated statement of operations and comprehensive loss.

The 2029 Notes include a discount which we amortize as an addition to the carrying value and treat as non-cash interest expense in the condensed consolidated statement of operations and comprehensive loss over the duration of the term.

The 2029 Notes will be redeemable, in whole or in part, at our option at any time, and from time to time, on or after June 20, 2027 and on or before the 50 th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the 2029 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date, but only if the last reported sale price per share of our common stock exceeds 130 % of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice and (ii) the trading day immediately before the date we send such notice.

In addition, calling any 2029 Note for redemption will constitute a “make-whole fundamental change” (as defined in the Indenture) with respect to that 2029 Note, in which case the conversion rate applicable to the conversion of that 2029 Note will be increased in certain circumstances if it is converted after it is called for redemption.

The Indenture contains customary terms and covenants and events of default.

If an event of default (other than certain events of bankruptcy, insolvency or reorganization involving the Company) occurs and is continuing, the Trustee or the holders of at least 25 % in aggregate principal amount of the 2029 Notes then outstanding may declare the principal amount of, and all accrued and unpaid interest on, all of the 2029 Notes then outstanding to become due and payable immediately.

Upon the occurrence of certain events of bankruptcy, insolvency or reorganization involving the Company, the principal amount of, and all accrued and unpaid interest, if any, on all of the 2029 Notes then outstanding will immediately become due and payable without any further action or notice by the Trustee or any holder.

Notwithstanding the foregoing, the Indenture provides that, to the extent we elect and for up to 180 days, the sole remedy for an event of default relating to certain failures by us to comply with certain reporting covenants in the Indenture may consist exclusively of the right to receive special interest on the 2029 Notes.

The 2029 Notes are structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of its subsidiaries.

Equitization Transaction

On May 12, 2025, we entered into Note Conversion Agreements with two holders of the 2026 Notes to convert $ 10.0 million aggregate principal amount of the 2026 Notes into shares of our common stock.

Under the terms of the Note Conversion Agreements, the holders agreed to convert the equitized principal amount of the 2026 Notes in three tranches for a number of shares of common stock to be determined based in part on the closing price of our common stock on May 9, 2025 and in part based on the 20 -day volume-weighted average price applicable to each tranche conversion date, subject to a floor conversion price.

Accordingly, the Equitization Transaction resulted in us initially recording a share-settled liability measured at fair value.

As of September 30, 2025, we completed the Equitization Transaction, resulting in the issuance of an aggregate of 2,819,866 shares of common stock to the two holders.

The Convertible Note Exchange transaction and Equitization Transaction reduced the aggregate principal balance of our 2026 Notes from $ 97.9 million to $ 17.1 million.

The $ 80.8 million reduction in aggregate principal amount of our 2026 Notes reflects the exchange of $ 70.8 million aggregate principal amount of 2026 Notes for the same principal amount of 2029 Notes under the Convertible Note Exchange and the reduction of $ 10.0 million in aggregate principal amount equitized under the Note Conversion Agreements.

The amount outstanding on the 2029 Notes is as follows:

September 30,

(In thousands)

1 unchanged sentence

Unamortized debt discount, net of issuance costs

Fair value of embedded derivative

Total unsecured convertible senior notes, net

Fair value of outstanding unsecured convertible senior notes (1)

Total 2029 Notes

Fair value of outstanding 2029 Notes (1)

Fair value of 2029 Notes embedded derivative (2)

The fair value is classified as a Level 2 liability due to the limited trading activity for the 2029 Notes.

This balance reflects the fair value of the 2029 Notes based on quoted prices in an over-the counter market using the most recent trading information at the end of the reporting period.

The fair value of the 2029 Notes embedded derivative is classified as a Level 3 liability due to unobservable inputs in which little or no market data exists.

(For further details refer to “Note 4 — Investments and Fair-Value Measurements”).

As of March 31, 2026, our only debt commitment relates to the 2029 Notes, which mature on June 15, 2029 .

Interest on the 2029 Notes is payable semi-annually in arrears at a rate of 9.50 % per annum on each June 15 and December 15, beginning on December 15, 2025.

The carrying value of the 2029 Notes includes a discount which we amortize over the duration of the term as non-cash interest expense in the consolidated statement of operations and comprehensive loss.

Due to the discount amortization on the 2029 Notes, interest expense is currently being recognized at an implied effective interest rate of 1.82 %.

The following table sets forth interest expense recognized related to the 2029 Notes:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Total interest expense

2024 Secured Term Loan

On June 3, 2024, we entered into a Credit Agreement with the Lenders, pursuant to which we have an outstanding Term Loan of $ 67.1 million.

All indebtedness under the Credit Agreement is secured by a first-priority security interest in and lien on substantially all our tangible and intangible property, subject to customary exceptions, and excluding royalty interests in OMIDRIA and certain related rights.

In connection with our entry into the Credit Agreement, we used the $ 67.1 million in Term Loan proceeds along with $ 21.7 million of cash on hand to repurchase $ 118.1 million aggregate principal amount of the 2026 Notes held by the Lenders.

The $ 29.3 million difference between the total consideration paid at closing of $ 88.8 million and the $ 118.1 million aggregate principal amount of the 2026 Notes was recorded as a premium (i.e., an increase) to the long-term debt on the Company’s condensed consolidated balance sheet.

The premium is being amortized as both a non-cash reduction of long-term debt in the condensed consolidated balance sheets and interest expense in the condensed consolidated statement of operations and comprehensive loss over the duration of the Term Loan.

The Transaction with Novo Nordisk is expected to close in the fourth quarter of 2025 and would provide us with $ 240.0 million in upfront cash, a portion of which would be applied to the full and immediate repayment of our $ 67.1 million principal outstanding under the Term Loan, along with a related prepayment premium, certain expenses and accrued and unpaid interest.

The amount outstanding on the Term Loan is as follows:

September 30,

(In thousands)

Principal amount

Unamortized debt premium, net of issuance costs and other

Fair value of embedded derivative

Total term debt, net

Fair value of outstanding term debt (1)

The fair value of the Term Loan is classified as a Level 3 liability.

We determine the fair market value by discounting future cash flows based on adjusted SOFR at each measurement date.

The Term Loan has a stated maturity date of June 3, 2028 and bears interest at an adjusted secured overnight financing rate (“adjusted SOFR”), subject to a 3.00 % floor, plus 8.75 % per annum, payable quarterly from the Closing Date.

As of September 30, 2025, the contractual interest rate on the Term Loan was 13.02 %.

We have the option to pay all of the interest in cash or to pay 50 % in cash and pay-in-kind (“PIK”), the remaining interest.

When this provision is elected, interest for the quarter, including both the cash interest and PIK interest, is calculated based on adjusted SOFR plus a 10.25 % PIK margin (instead of the customary 8.75 % margin).

The PIK interest is then added to the outstanding principal balance and interest is computed using the original adjusted SOFR plus 8.75 % margin rate.

Due to the premium amortization on the Term Loan, interest expense is currently being recognized at an implied effective interest rate of 3.36 %.

The 2029 Notes are redeemable, in whole or in part, at our option at any time, and from time to time, on or after June 20, 2027 and on or before the 50 th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the 2029 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date, but only if the last reported sale price per share of our common stock exceeds 130 % of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice and (ii) the trading day immediately before the date we send such notice.

In addition, calling any 2029 Note for redemption would constitute a “make-whole fundamental change” (as defined in the Indenture) with respect to that 2029 Note, in which case the conversion rate applicable to the conversion of that 2029 Note would be increased in certain circumstances if it is converted after it is called for redemption.

On June 3, 2024, we entered into a Credit and Guarantee Agreement with funds managed by Athyrium Capital Management LP and funds managed by Highbridge Capital Management, LLC, as lenders, pursuant to which we had an outstanding Term Loan of $ 67.1 million.

The Transaction with Novo Nordisk, which closed on November 25, 2025, provided us with $ 240.0 million in upfront cash of which we used a portion at the time of closing to repay the entire $ 67.1 million outstanding principal amount of the Term Loan, along with a related prepayment premium, certain expenses and accrued and unpaid interest.

The following table sets forth interest expense recognized related to the Term Loan:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Total interest expense

We may elect to prepay the Term Loan, in whole or in part, in cash, plus an applicable prepayment and/or make-whole premium.

Under certain circumstances, we are required to prepay all or a portion of the outstanding Loans, plus an applicable prepayment and/or make-whole premium, as described below.

(1) As a result of the Convertible Note Exchange completed on May 14, 2025, a prepayment requirement under the Term Loan was no longer applicable because the outstanding principal amount under the 2026 Notes was reduced below $ 38.5 million.

As a result, the accompanying condensed consolidated balance sheet as of September 30, 2025 reflects the entire Term Loan as a long-term liability.

(2) Upon the occurrence of a change in control, we must prepay the entire outstanding amount of the Term Loan, plus the applicable make-whole or prepayment premium.

(3) We must prepay the outstanding Term Loan in an amount equal to:

(i) 25.0 % of any milestone payments received from DRI or its affiliates on the basis of net sales of OMIDRIA;

(ii) 60.0 % of the net cash proceeds (excluding transaction expenses and certain milestone payments) received by Omeros from the sale or license of our assets;

(iii) 100.0 % of net cash proceeds of indebtedness incurred by the Company other than as permitted by the Credit Agreement;

and (iv) 100.0 % of the net cash proceeds of insurance recoveries on loss of property, except to the extent utilized to repair or replace the relevant assets within a specified time.

In connection with the anticipated closing of the Transaction with Novo Nordisk, we will be required to repay the full amount of the Term Loan principal of $ 67.1 million, a prepayment premium, certain expenses and accrued and unpaid interest.

Voluntary and mandatory prepayments of the Term Loan are subject to payment of the following premiums:

(i) during the first year of such amounts are outstanding under the Term Loan, a make-whole premium plus 5.0 % of the applicable prepayment amount (unless the prepayment is made in contemplation of a change of control, in which case only the make-whole premium would be payable);

(ii) during the second year, a prepayment premium equal to 5.0 % of the applicable prepayment amount;

and (iii) during the third year, a prepayment premium equal to 3.0 % of the applicable prepayment amount.

The Credit Agreement contains certain customary default provisions, representations and warranties and affirmative and negative covenants.

These include a covenant requiring us to maintain at all times unrestricted cash, cash equivalents and short-term investments of at least $ 25.0 million in accounts subject to control agreements.

As of September 30, 2025 and through the date of issuance of these condensed consolidated financial statements, the Company was in compliance with the covenants under the Credit Agreement.

A default under the Credit Agreement that results in the outstanding debt thereunder being declared due and payable prior to the stated maturity would constitute a cross-default under the indenture governing the 2026 Notes and the 2029 Notes, as applicable.

In such an event, the principal and all accrued and unpaid interest on the 2026 Notes and the 2029 Notes may be declared immediately due and payable either by the trustee under the applicable indenture, or by holders of at least 25 % of the aggregate outstanding principal amounts of the 2026 Notes and the 2029 Notes, respectively.

The Transaction with Novo Nordisk would result in the release in full of all liens and covenants thereunder including the covenant whereby we must maintain a minimum $25.0 million of unrestricted cash, cash equivalents and short-term investments at all times.

2026 Unsecured Convertible Senior Notes

We have outstanding unsecured convertible senior notes which accrue interest at an annual rate of 5.25 % per annum, payable semi-annually in arrears on February 15 and August 15 of each year.

The 2026 Notes mature on February 15, 2026 , unless earlier purchased, redeemed or converted in accordance with their terms.

In 2024, we repurchased $ 118.1 million of principal amount outstanding on our 2026 Notes for total consideration of $ 88.8 million (approximately 75 % of par value) , using proceeds from the Term Loan of $ 67.1 million and paying $ 21.7 million of cash on hand.

On May 14, 2025, we completed the Convertible Note Exchange in which we exchanged $ 70.8 million in aggregate principal of our 2026 Notes for a like principal amount of our 2029 Notes.

On May 12, 2025, we entered into the Equitization Transaction, which resulted in the conversion of an additional $ 10.0 million aggregate principal amount of 2026 Notes into 2,819,866 shares of our common stock.

The principal balance of our 2026 Notes was reduced from $ 97.9 million to $ 17.1 million as a result of the Convertible Note Exchange and Equitization Transaction.

Amounts outstanding on our 2026 Notes as of September 30, 2025 and December 31, 2024 are as follows:

September 30,

2026 Convertible Senior Notes

We had outstanding convertible senior notes that accrued interest at an annual rate of 5.25 % per annum, payable semi-annually in arrears on February 15 and August 15 of each year.

The 2026 Notes matured on February 15, 2026 and were paid in full at that time.

Amounts outstanding on our 2026 Notes as of March 31, 2026 and December 31, 2025 are as follows:

(In thousands)

1 unchanged sentence

Unamortized debt issuance costs

Total unsecured convertible senior notes, net

Fair value of outstanding unsecured convertible senior notes (1)

The fair value is classified as Level 2 liability due to the limited trading activity for the 2026 Notes.

This balance reflects the fair value of the 2026 Notes based on quoted prices in an over-the counter market using the most recent trading information at the end of the reporting period.

The value of the conversion feature of the 2026 Notes is not deemed to be significant as the current market price of our common stock is below the initial conversion price of $ 18.49 per share of common stock.

The $ 80.8 million reduction in aggregate principal amount of our 2026 Notes reflects the exchange of $ 70.8 million aggregate principal amount of 2026 Notes for 2029 Notes under the Convertible Note Exchange and the reduction of $ 10.0 million in aggregate principal amount equitized under the Note Conversion Agreements.

We have amortized interest expense on the 2026 Notes at an effective interest rate of 5.89 %.

Total 2026 Notes

Fair value of outstanding 2026 Notes (1)

The fair value was classified as Level 2 liability due to the limited trading activity for the 2026 Notes.

The balance as of December 31, 2025 reflected the fair value of the 2026 Notes based on quoted prices in an over-the counter market using the most recent trading information at the end of the reporting period.

The value of the conversion feature of the 2026 Notes was not deemed to be significant as no holders converted their notes prior to repayment.

The following table sets forth interest expense recognized related to the 2026 Notes:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Total interest expense

The conversion rate is 54.0906 shares of our common stock per $ 1,000 of note principal (equivalent to an initial conversion price of approximately $ 18.4875 per share of common stock), which equals approximately 1.3 million shares issuable upon conversion, subject to adjustment in certain circumstances.

The 2026 Notes are convertible at the option of the holders on or after November 15, 2025 at any time prior to the close of business on February 12, 2026, the second scheduled trading day immediately before the stated maturity date of February 15, 2026 .

Additionally, holders may convert their 2026 Notes at their option at specified times prior to the maturity date only if:

(1) during any calendar quarter, the last reported sale price per share of our common stock exceeds 130 % of the conversion price of the 2026 Notes for each of at least 20 trading days, whether or not consecutive, in the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter;

(2) during the five consecutive business days immediately after any five -consecutive-trading-day period (such five -consecutive-trading-day period, the “measurement period”) in which the trading price per $ 1,000 principal amount of 2026 Notes for each trading day of the measurement period was less than 98 % of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day;

(3) there is an occurrence of one or more certain corporate events or distributions of our common stock;

(4) we call the 2026 Notes for redemption.

We will settle any conversions by paying or delivering, as applicable, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on the applicable conversion rate(s).

Subject to the satisfaction of certain conditions, we may redeem in whole or in part the 2026 Notes at our option through the 50 th scheduled trading day immediately before the maturity date at a cash redemption price equal to the principal amount of the 2026 Notes to be redeemed plus any accrued and unpaid interest.

The 2026 Notes are subject to redemption only if certain requirements are satisfied, including that the last reported sale price per share of our common stock exceeds 130 % of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice and (ii) the trading day immediately before the date we send such notice.

In order to reduce the dilutive impact or potential cash expenditure associated with the conversion of the 2026 Notes, we entered into capped call transactions in connection with the issuances of the 2026 Notes (the “2026 Capped Call”).

The 2026 Capped Call will cover, subject to anti-dilution adjustments substantially similar to those applicable to the 2026 Notes, the number of shares of common stock underlying the 2026 Notes when our common stock is trading within the range of approximately $ 18.49 and $ 26.10 .

However, should the market price of our common stock exceed the $ 26.10 cap, then the conversion of the 2026 Notes would have an additional dilutive impact or may require a cash expenditure to the extent the market price of our common stock exceeds the cap price.

The 2026 Capped Call will expire on various dates over the 50 -trading-day period ranging from December 2, 2025 to February 12, 2026, if not exercised earlier.

The 2026 Capped Call is a separate transaction and not part of the terms of the 2026 Notes and was executed separately from the issuance of the 2026 Notes.

The amount paid for the 2026 Capped Call was recorded as a reduction to additional paid-in capital in the condensed consolidated balance sheet.

As of September 30, 2025, approximately 12.2 million shares remained outstanding under the 2026 Capped Call.

We also retain all potential future value of the capped call purchased in connection with the issuance of the 2026 Notes covering all shares underlying the original 2026 Notes.

The capped call will expire on the maturity date of the 2026 Notes.

Further, we concluded the 2026 Capped Call qualifies for a derivative scope exception for instruments that are both indexed to an entity’s own stock and classified in stockholders’ equity in its balance sheet.

Consequently, the fair value of the 2026 Capped Call of $ 23.2 million is classified as equity, not accounted for as derivatives, and will not be subsequently remeasured.

Minimum Commitments

As of September 30, 2025, the contractual principal payments on our 2026 Notes, Term Loan and 2029 Notes are as follows:

(In thousands)

2029 and thereafter

Total principal payments

Net unamortized premiums, discounts, derivatives and issuance costs

Carrying value of debt

Under the terms of the Credit Agreement, the Company will be required to repay all outstanding obligations related to the Term Loan upon closure of the Transaction with Novo Nordisk, which is expected to occur in the fourth quarter of 2025.

Note 7 — Discontinued Operations - Sale of OMIDRIA

2 unchanged sentences

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Other income (loss), net

Ex-US royalties

Net income (loss) from discontinued operations, net of tax

Income before income tax

Income tax benefit

Net income from discontinued operations, net of tax

The following is a roll-forward of the OMIDRIA contract royalty asset (in thousands):

3 unchanged sentences

Remeasurement adjustments

OMIDRIA contract royalty asset at September 30, 2025

OMIDRIA contract royalty asset at March 31, 2026

We remeasure the OMIDRIA contract royalty asset on a quarterly basis using the expected value approach, which incorporates actual results and future expectations.

Cash flow from discontinued operations is as follows:

Nine Months Ended

September 30,

Three Months Ended

(In thousands)

4 unchanged sentences

Note 8 — OMIDRIA Royalty Obligation

In September 2022, we sold to DRI an interest in our future OMIDRIA royalty receipts and received $ 125.0 million in cash consideration, which was recorded as an OMIDRIA royalty obligation on our condensed consolidated balance sheet.

DRI was entitled to receive royalties on OMIDRIA net sales between September 1, 2022 and December 31, 2030, subject to annual caps.

In February 2024, Omeros and DRI expanded their royalty purchase agreement under the Amendment, resulting in the elimination of previously existing annual caps on royalty payments and Omeros receiving an additional $ 115.5 million in cash consideration, which we accounted for as a modification of our existing debt from DRI.

On September 30, 2022, we sold to DRI a portion of our future OMIDRIA royalty receipts for a purchase price of $ 125.0 million and recorded an OMIDRIA royalty obligation for the same amount.

On February 1, 2024, DRI purchased our remaining U.S.

OMIDRIA royalty receipts through December 31, 2031 for $ 115.5 million in cash under the Amendment.

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.

We accounted for the Amendment as a modification of our existing debt from DRI.

The OMIDRIA royalty obligation is valued based on our estimates of future OMIDRIA royalties and is amortized through 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 right to receive all royalties payable by Rayner on any U.S.

net sales of OMIDRIA after December 31, 2031 and on all royalties on global net sales of OMIDRIA payable from and after December 31, 2031.

DRI has no recourse to our assets other than in its interest in OMIDRIA royalties.

We currently retain the right to receive all royalties payable by Rayner on any ex-U.S.

After December 31, 2031, we retain the right to receive all global royalties payable by Rayner on net sales of OMIDRIA.

To date, international royalties have not been significant.

DRI has no recourse to our assets other than its interest in OMIDRIA royalties.

We are also entitled to receive a milestone payment ranging between $ 10.0 million and $ 27.5 million if U.S.

net sales of OMIDRIA reach applicable thresholds ranging between a total of $ 156.0 million and $ 160.0 million in the aggregate for any period of four consecutive quarters prior to January 1, 2026.

We do not expect to receive this milestone payment.

In addition, 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 in the aggregate for any period of four consecutive quarters prior to January 1, 2028.

The changes in the OMIDRIA royalty obligation during the nine months ended September 30, 2025 are as follows (in thousands):

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 in the aggregate for any period of four consecutive quarters prior to January 1, 2028, although we do not expect to receive this milestone based on current U.S.

net sales of OMIDRIA.

The changes in the OMIDRIA royalty obligation during the three months ended March 31, 2026 are as follows (in thousands):

Balance at December 31, 2025

Remeasurement on the OMIDRIA royalty obligation

Non-cash interest

Principal payments

Balance at September 30, 2025

Balance at March 31, 2026

The OMIDRIA royalty obligation is classified as a Level 3 liability as its valuation requires substantial judgment and estimation of factors that are not currently observable in the market.

The fair value of the OMIDRIA royalty obligation is determined by calculating the net present value of our estimated future OMIDRIA cash flows using the interest rate at inception of our royalty purchase agreement with DRI, adjusted for the change in the prime rate through the measurement date.

As of September 30, 2025 and December 31, 2024, the approximate fair value of our obligation was $ 168.2 million and $ 209.7 million, respectively .

As of March 31, 2026 and December 31, 2025, the approximate fair value of our obligation was $ 160.7 million and $ 166.7 million, respectively .

Interest expense is comprised of the effective interest component of any cash payment remitted through an administrative agent to DRI, based on an implied effective interest rate of 9.92 %, and any remeasurement adjustments taken during the period.

Remeasurements are non-cash adjustments to the OMIDRIA royalty obligation reflecting changes in forecasted cash flows stemming from the OMIDRIA contract royalty asset.

For the three and nine months ended September 30, 2025 and 2024, interest expense is as follows:

For the three months ended March 31, 2026 and 2025, interest expense is as follows:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Interest expense, net of remeasurement on OMIDRIA royalty obligation

As of September 30, 2025, the expected scheduled principal and interest payments are as follows:

As of March 31, 2026, the expected scheduled principal and interest payments are as follows:

(In thousands)

2 unchanged sentences

Note 9 — Lease Liabilities

We have an operating lease for our office and laboratory facilities with an initial term that ends in November 2027 and two options to extend the lease term by an additional five years each.

We have an operating lease for our office and laboratory facilities with an initial term that ends in November 2027 and two options to extend the lease term, each by an additional five years.

Restricted investments of $ 1.1 million represent the security deposit on our office and laboratory facilities.

2 unchanged sentences

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

5 unchanged sentences

The supplemental cash flow information related to leases is as follows:

Nine Months Ended

September 30,

Three Months Ended

(In thousands)

4 unchanged sentences

Good and Service Contracts

We have various agreements with third parties that collectively require payment of termination fees totaling $ 3.2 million as of September 30, 2025 if we cancel the work within specific time frames, either prior to commencing or during performance of the contracted services.

We have various agreements with third parties that collectively require payment of termination fees totaling $ 25.8 million as of March 31, 2026 if we cancel the work within specific time frames, either prior to commencing or during performance of the contracted services.

Development Milestones and Product Royalties

We have entered a variety of development, collaboration, licensing or similar agreements with third parties under which we have accessed technology or services in connection with our development assets and programs.

Some of these agreements require milestone payments based on achievements of development, regulatory or sales milestones, and/or low-single to low-double digit royalties on net income or net sales of the relevant product.

For the three and nine months ended September 30, 2025 and 2024, development milestone expenses were not significant.

Some of these agreements require milestone payments based on achievements of development, regulatory or sales milestones, and/or very low-single digit royalties on net income or net sales of the relevant product.

For the three months ended March 31, 2026 and 2025, royalties on sales of YARTEMLEA and development milestone expenses were not significant.

Note 11 — Shareholders ’ Deficit

At-the-Market Sales Agreement - We have a sales agreement to sell shares of our common stock having an aggregate offering price of up to $ 150.0 million, from time to time, through an ATM equity offering program.

During the three months ended September 30, 2025, we sold 2.3 million shares of common stock pursuant to our ATM program, generating $ 9.0 million at an average price per share of $ 3.99 .

During the nine months ended September 30, 2025, we sold 3.7 million shares of common stock generating net proceeds of $ 15.3 million at an average price per share of $ 4.24 .

Subsequent to September 30, 2025, we sold 0.6 million shares of common stock, generating net proceeds of $ 3.6 million at an average price per share of $ 6.11 .

Share Repurchase Program - 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.

During the six months ended June 30, 2024, we repurchased and retired 3.2 million shares of common stock for an average price per share of $ 3.71 at an aggregate cost of $ 11.9 million.

The terms of the Credit Agreement prohibit 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.

Equitization Transaction - On May 12, 2025, we entered into Note Conversion Agreements with two holders of the 2026 Notes, which resulted in the conversion of $ 10.0 million aggregate principal amount of 2026 Notes into 2,819,866 shares of our common stock.

(For further details, see “Note 6 – Debt”).

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 Polar 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 the shares.

We received $ 20.3 million in cash proceeds net of offering expenses.

At-the-Market Sales Agreement - We have an “at the market” (“ATM”) facility agreement under which we have the capability to sell shares of our common stock, from time to time, through an ATM equity offering program.

On November 14, 2025, the Company filed a shelf registration statement and prospectus supplement renewing the ATM for an aggregate offering price of up to $ 150.0 million.

As of the date of this report, we have $ 150.0 million in shares of our common stock available to sell under our ATM program.

Share Repurchase Program - On November 29, 2025, the Board of Directors approved a 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.

For the three months ended March 31, 2026, we repurchased and retired 0.4 million shares of common stock at an average cost of $ 11.70 for an aggregate purchase price of $ 4.2 million.

Note 12 — Stock-Based Compensation

Our stock option plans provide for the grant of incentive and non-qualified stock options, restricted stock awards, restricted stock units, and other stock awards to employees, non-employee directors, and consultants.

Our equity incentive plans provide for the grant of incentive and non-qualified stock options, restricted stock awards, restricted stock units, and other stock awards to employees, non-employee directors, and consultants.

Stock-based compensation is as follows:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

5 unchanged sentences

Three Months Ended

Nine Months Ended

September 30, 2025

March 31, 2026

Estimated weighted-average fair value

13 unchanged sentences

Balance at December 31, 2025

Balance at September 30, 2025

Vested and expected to vest at September 30, 2025

Exercisable at September 30, 2025

Through September 30, 2025, stock options to purchase an aggregate of approximately 3.3 million shares of our common stock were awarded to eligible participants under the 2017 Omnibus Incentive Compensation Plan in connection with annual refresh grants.

Of the 19.5 million common stock options outstanding as of September 30, 2025, options to purchase 8.3 million shares have an exercise price per share above $ 4.10 , which was the closing price of our stock on the Nasdaq Global Market on September 30, 2025.

As of September 30, 2025, there were 6.3 million unvested options outstanding that will vest over a weighted-average period of 2.6 years.

Balance at March 31, 2026

Vested and expected to vest at March 31, 2026

Exercisable at March 31, 2026

Of the 17.2 million common stock options outstanding as of March 31, 2026, options to purchase 6.0 million shares have an exercise price per share above $ 10.56 , which was the closing price of our stock on the Nasdaq Global Market on March 31, 2026.

As of March 31, 2026, there were 4.9 million unvested options outstanding that will vest over a weighted-average period of 2.5 years.

The total estimated compensation expense yet to be recognized on outstanding options is $ 11.4 million.

As of September 30, 2025, the total number of shares of common stock available for grant was 4.0 million.

As of March 31, 2026, the total number of shares of common stock available for grant was 3.9 million.

MANAGEMENT ’ S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

1 unchanged sentence

In addition, you should read the section entitled “ Risk Factors ” and the disclaimers regarding forward-looking statements included herein and in our Annual Report on Form 10-K for the year ended December 31, 2025 for a discussion of important factors that could cause our results to differ materially from the results described in or implied by any forward-looking statements contained herein.

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

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

4 unchanged sentences

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 activation of the targeted pathway 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

2 unchanged sentences

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 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.

As previously disclosed, in March 2025, the Company resubmitted to the U.S.

Food and Drug Administration (“FDA”) the biologics license application (“BLA”) seeking regulatory approval for narsoplimab in hematopoietic stem cell transplant-associated thrombotic microangiopathy (“TA-TMA”).

The resubmission was accepted for review by FDA as a class 2 resubmission and, pursuant to the Prescription Drug User Fee Act (“PDUFA”), was assigned an initial target action date for the FDA decision of September 25, 2025.

Following the submission of information in response to a request from FDA, FDA informed us that the PDUFA date has been extended to December 26, 2025.

We expect that FDA will meet this PDUFA date.

In June 2025, we submitted a Marketing Authorization Application (“MAA”) for narsoplimab for the treatment of TA-TMA in the European Union.

The European Medicines Agency (“EMA”) completed validation of the narsoplimab MAA, which confirms that the submission is accepted and starts the formal review process by EMA’s Committee for Medicinal Products for Human Use.

We expect an opinion on the MAA in mid-2026.

As with any BLA or MAA, there can be no guarantee that FDA or the EMA will complete their respective reviews within a given timeframe, or that the Company’s BLA or MAA will ultimately be approved.

Our pipeline also includes 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 a program focused on development of an orally administered small-molecule MASP-2 inhibitor.

In the first quarter of 2025 we determined to pause most development activities in our OMS1029 and MASP-2 small-molecule development programs to preserve available capital for narsoplimab and other prioritized programs.

Alternative Pathway / MASP-3

Our pipeline of clinical-stage complement-targeted therapeutic candidates also includes zaltenibart (OMS906), a proprietary, patented monoclonal antibody targeting MASP-3, the key activator of the alternative pathway of complement.

We believe zaltenibart has the potential to treat a wide range of alternative pathway-related diseases and that its attributes favorably differentiate zaltenibart from other marketed and in-development alternative pathway inhibitors.

Our clinical development of zaltenibart has been focused on PNH and C3G.

We have substantially completed two Phase 2 clinical trials evaluating zaltenibart and have an ongoing open label extension study to assess the long-term efficacy and safety of zaltenibart in PNH patients who have completed either of the two Phase 2 clinical trials.

We also have a small, ongoing Phase 2 study evaluating zaltenibart in C3G.

On October 10, 2025, we entered into an Asset Purchase and License Agreement (the “APLA”) with Novo Nordisk Health Care AG (“Novo Nordisk”), pursuant to which Novo Nordisk will receive exclusive global rights in all indications to develop and commercialize zaltenibart in consideration of certain upfront and contingent payments payable to us (the “Transaction”) upon the Closing (as defined below).

Our ongoing and planned clinical programs for zaltenibart will be transitioned to Novo Nordisk following the Closing of the Transaction throughout which we will provide certain transition services to Novo Nordisk.

Subject to the satisfaction or waiver of the foregoing conditions and the other terms and conditions contained in the APLA, the Transaction is expected to close in the fourth quarter of 2025.

Following the Closing and during the term of the APLA, we and our affiliates will be restricted from exploiting products directed to MASP-3 and certain other alternative pathway targets, subject to certain exceptions for retained preclinical program rights (outside of zaltenibart), products of an acquirer, and non-competing indications.

We will retain rights to continue development of our existing MASP-3 small-molecule program, including the ability to develop and commercialize small-molecule inhibitors with limited indication-related restrictions.

We will 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.

See 2025 Asset Purchase and License Agreement below for further information regarding the Transaction.

PDE7 Inhibitor Programs

In April 2023, we were awarded a grant from the National Institute on Drug Abuse (“NIDA”), part of the National Institutes of Health, to develop our lead orally administered PDE7 inhibitor compound for the treatment of cocaine use disorder.

NIDA awarded the grant to us for a total of $6.24 million over three years, of which we expensed $2.1 million and have claimed and received $1.6 million of funding to date.

The preclinical studies, which were designed with NIDA toxicologists, have been successfully completed with no safety findings and provide drug-interaction safety data in support of the planned in-patient human study of OMS527 in cocaine users.

FDA has requested that we provide additional preclinical information prior to initiating the clinical in-patient study in cocaine users, which we are targeting for the second half of 2026.

Preclinical Programs - Oncology Platform

We are developing a portfolio of signaling-driven immunomodulators, oncotoxins, and an adoptive T-cell technology combined with an immunostimulator that, unlike other cellular therapy approaches requires no cellular engineering, may reduce manufacturing costs and timelines, and may maintain an enhanced anti-cancer immune response through subsequent repetitive and simple therapeutic administrations.

We continue on a limited basis to progress pre-clinical studies within our novel oncology program, including IND-enabling studies in our program to develop novel, proprietary large molecule therapeutics designed to target and kill only dividing cancer cells.

Acute myeloid leukemia (“AML”) is the lead indication for development in this program, which we refer to as OncotoX-AML.

In preclinical models both in vivo – in immunocompromised mice with human tumors – and in vitro , our potential AML therapeutic has consistently demonstrated superior efficacy to current AML standard of care treatments and has been well-tolerated in preliminary, preclinical tolerability studies.

A non-human primate safety study is underway, with encouraging results to date.

Our OncotoX-AML therapeutic also shows broad potential application across AML regardless of genetic mutation, including TP53, NPM1, KMT2A, and FLT3.

Importantly, inhibition of MASP-2 has been demonstrated not to interfere with the antigen-antibody complex-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) was approved by the Food and Drug Administration (“FDA”) in December 2025 and is commercially available in the U.S.

for the treatment of TA-TMA in adult and pediatric patients aged two years and older.

For more information, see “ Commercial Product – YARTEMLEA ” below.

Clinical development of narsoplimab is anticipated to continue expanding the approved label in TA-TMA and to develop the drug in additional indications.

Clinical development efforts have previously been directed to acute respiratory distress syndrome (“ARDS”), including severe acute COVID-19, which can result in post-acute sequelae of SARS-CoV-2 infection (“PASC,” i.e., long COVID).

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.

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.

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 pathway 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.

Unlike other complement inhibitors, YARTEMLEA has no boxed warning and no Risk Evaluation and Mitigation Strategy (REMS), and vaccinations are not required prior to treatment.

Commercial distribution and sales of YARTEMLEA began in January 2026.

Both adult and pediatric patients with TA-TMA are now receiving YARTEMLEA, including patients who have recently failed prior off-label C5- and C3-inhibitor regimens, in both hospital and outpatient settings.

We are commercializing YARTEMLEA in the U.S.

market and have deployed our field force of account managers and directors, market development managers, access leads, and medical science liaisons to engage directly with transplant centers across the U.S.

There are 175 stem-cell transplant centers across the U.S., with the top 80 centers representing approximately 80% of procedures.

Our field force is detailing all 175 transplant centers nationwide.

By March 31, 2026, 30 unique accounts had ordered YARTEMLEA.

At this early stage, our primary launch objectives are fourfold:

(i) educate the entire transplant care team, including transplant physicians, nurses, hospital pharmacies, and reimbursement teams, regarding the recently harmonized TA-TMA diagnostic criteria, thereby driving awareness, early diagnosis, and treatment of TA-TMA;

(ii) support transplant centers in obtaining their pharmacy and therapeutic committee approvals and adding YARTEMLEA to their formularies to streamline the ordering process and facilitate access to YARTEMLEA in both the in- and out-patient settings;

(iii) work with third-party payers to provide timely reimbursement consistent with the YARTEMLEA label and published diagnostic criteria;

and (iv) finalize and prepare for publication of the health economics and outcomes research analysis using the strong clinical efficacy data and favorable safety profile of YARTEMLEA to demonstrate its compelling cost-effectiveness to healthcare providers and payors.

An MAA for YARTEMLEA in TA-TMA has been submitted to the EMA and is being reviewed under EMA’s centralized review procedure, which allows review of a single marketing authorization application.

If the MAA is approved, it would authorize the product to be marketed in all European Union (“EU”) member states and European Economic Area countries.

The European Commission has granted narsoplimab designation as an orphan medicinal product for treatment in hematopoietic stem cell transplantation.

For commercialization of YARTEMLEA outside the U.S., we are evaluating potential partnerships, including broad ex-U.S.

and regional collaborations.

Sale of Zaltenibart / MASP-3

On November 25, 2025, we completed a transaction (the “Transaction”) pursuant to our Asset Purchase and Licensing Agreement (“APLA”) with Novo Nordisk Healthcare AG (“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.

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 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.

Other Development Programs

PDE7 Inhibitor Program

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 nonclinical information prior to initiating the clinical in-patient study.

Following a meeting with FDA to discuss that request, we are working with FDA to streamline the path to initiate the in-patient clinical trial, which which is targeted for initiation by year-end 2026.

Preclinical Program - OncotoX -AML

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.

Acute myeloid leukemia (“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.

In February 2026, we announced the successful completion of our initial study in nonhuman primates evaluating the efficacy and safety of OncotoX -AML.

Administration of only one course of OncotoX -AML treatment to immunocompetent primates demonstrated the desired pharmacologic response, specifically marked, selective, reversible, and dose-related reduction in myeloid progenitor cells — the cells that can mutate and lead to AML — by up to 99%.

OncotoX -AML was well tolerated, without causing broader or lasting hematologic changes while preserving hematopoietic stem cells.

There were no observed safety signals or meaningful changes in blood chemistry values often seen with current AML treatments.

In April 2025, we established the Omeros Oncology Clinical Steering Committee to help advance our OncotoX -AML program.

The clinical steering committee is composed of leaders in AML treatment and research at the premier cancer centers across the United States.

These experts in the treatment of AML are expected to help guide clinical development of our potential AML therapeutic.

IND-enabling work is ongoing with an estimated timeline to clinical entry of 18-24 months.

We continue to confirm our results and to generate new data which we expect will contribute to our intellectual property position.

Preclinical Programs - T-CAT

We are also advancing our Targeted Complement Activating Therapy (“T-CAT”) platform – a new class of pathogen-targeting recombinant antibodies intended for broad action against bacteria, fungi, viruses, and parasites.

The clinical steering committee is comprised of leaders in AML treatment and research at premier cancer centers.

Together with this steering committee, we are designing our first in-human clinical trial.

IND-enabling studies and manufacturing development work is ongoing within our OncotoX -AML program with the goal of entering the clinic by late 2027.

Preclinical Program - T-CAT

We are also advancing our targeted complement activating therapy (“T-CAT”) platform:

a new class of recombinant antibodies intended for broad action against pathogens, including 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.

1 unchanged sentence

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.

2025 Asset Purchase and License Agreement

On October 10, 2025, we entered into the APLA with Novo Nordisk, pursuant to which Novo Nordisk will receive exclusive global rights in all indications to develop and commercialize zaltenibart and certain related monoclonal antibodies and antigen-binding fragments (collectively, the “Compounds”), and related pharmaceutical products (“Products”) upon the Closing.

Pursuant to the terms and subject to the conditions of the APLA, we are eligible to receive $340.0 million in upfront and near-term milestone payments, of which $240.0 million is to be received by us at the closing of the Transaction (the “Closing”).

Beyond the $340.0 million, we can receive (i) an additional $410.0 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.

2024 Term Loan and Repurchase of 2026 Notes

On June 3, 2024 (the “Closing Date”), we, with certain subsidiaries, as guarantors, entered into the Credit and Guaranty Agreement (the “Credit Agreement”) with 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.

The Credit Agreement provides for a senior secured term loan facility of $67.1 million (the “Term Loan”).

In 2024, we used the $67.1 million Term Loan proceeds, along with $21.7 million of cash on hand to repurchase from the Lenders $118.1 million aggregate principal amount of our existing 5.25% convertible senior notes due on February 15, 2026 (the “2026 Notes”), which resulted in a $51.0 million reduction in our total outstanding debt.

The $29.3 million difference between the total consideration paid at closing of $88.8 million and the $118.1 million aggregate principal amount of the 2026 Notes was recorded as a premium (i.e., an increase) on the Term Loan.

All indebtedness outstanding under the Credit Agreement is guaranteed by certain of our direct and indirect subsidiaries, other than certain foreign subsidiaries that are not material (we and the guarantors, collectively, the “Credit Parties”).

Pursuant to a Pledge and Security Agreement, dated June 3, 2024, the indebtedness under the Credit Agreement is secured by a first-priority security interest in and lien on substantially all tangible and intangible property of the Credit Parties, subject to customary exceptions, and excluding royalty interests in OMIDRIA and certain related rights.

Amounts outstanding under the Term Loan accrue interest at an adjusted term secured overnight financing rate, (“adjusted term SOFR”) (with a 3.00% floor) plus 8.75% per annum, payable quarterly.

The Credit Agreement has a scheduled maturity date of June 3, 2028.

As of September 30, 2025, the contractual interest rate on the Term Loan was 13.02%.

The Credit Agreement contains certain customary default provisions, representations and warranties and affirmative and negative covenants, including a covenant for the Credit Parties to maintain at all times unrestricted cash, cash equivalents and short-term investments of at least $25.0 million in accounts subject to control agreements, and a covenant limiting the use of cash for open market or privately negotiated repurchases of any outstanding 2026 Notes.

The Credit Agreement requires mandatory prepayments of outstanding Term Loans in an amount equal to 60% of the net cash proceeds (excluding research and development and certain other milestone-based payments) received by the Credit Parties from asset sales and licenses, including the Transaction with Novo Nordisk.

The Transaction with Novo Nordisk is expected to close in the fourth quarter of 2025 and would provide us with $240.0 million in upfront cash, a portion of which will be applied to the mandatory repayment of the entire $67.1 million principal outstanding under the Term Loan, along with a 5.0% prepayment premium, certain expenses and accrued and unpaid interest.

The repayment will result in the release in full of all liens and covenants thereunder including the $25.0 million minimum liquidity covenant.

See “Note 6 — Debt” in the Notes to Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q for further details.

Convertible Note Exchange and Equitization Transaction

On May 14, 2025, we completed with a limited number of holders of the 2026 Notes the exchange (the “Convertible Note Exchange”) of $70.8 million aggregate principal amount of our 2026 Notes on a one-for-one basis for newly-issued convertible senior notes maturing on June 15, 2029 (the “2029 Notes”).

On May 12, 2025, we entered into 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 (the “Equitization Transaction”) in three tranches.

As of September 30, 2025, we completed the Equitization Transaction, resulting in the issuance of an aggregate of 2,819,866 shares to the two holders.

The aggregate principal balance of our 2026 Notes was reduced from $97.9 million to $17.1 million as a result of the Convertible Note Exchange and Equitization Transaction.

No new cash was received as a result of these transactions.

We also retain all potential future value of the capped call purchased in connection with the issuance of the 2026 Notes covering all shares underlying the aggregate principal amount of the originally issued 2026 Notes.

The capped call will expire on the maturity date of the 2026 Notes.

See “Note 1 — Organization and Basis of Presentation” and “Note 6 — Debt” in the Notes to Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q for further details.

We are currently working to complete preclinical proof of concept studies and evaluate data for several infectious diseases.

Debt Financing Transactions

Exchange of 2026 Notes for 2029 Notes

On May 14, 2025, we completed the exchange (the “Convertible Note Exchange”) of $70.8 million of our 5.25% convertible senior notes (the “2026 Notes”) on a one-for-one basis for newly issued convertible senior notes maturing on June 15, 2029 (the “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 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 condensed consolidated statement of operations and comprehensive income (loss).

At contract inception, we recorded a net $23.0 million embedded derivative as a component of our 2029 Notes.

See “Note 6 — Debt — 2029 Notes — Embedded Derivative ” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q for further details.

Repayment of Debt

On November 25, 2025, concurrent with the closing of the sale and licensing of zaltenibart to Novo Nordisk under the APLA, we were required under that certain Credit and Guarantee Agreement, dated June 3, 2024 (the “Credit Agreement”) to repay in full the $67.1 million principal balance outstanding (the “Term Loan”) along with a 5% prepayment premium.

Repayment of our obligations under the Credit Agreement resulted in the release in full of all liens and covenants thereunder.

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

Equity Financing Transactions

At the Market Sales Agreement

We have an “at the market” (“ATM”) facility agreement under which we have the capability to sell shares of our common stock from time to time, through an ATM equity offering program.

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.

We did not sell any shares under the ATM program during the three months ended March 31, 2026.

Share Repurchase Programs

On November 29, 2025, the Board of Directors approved a 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.

During the three months ended March 31, 2026, we repurchased and retired 0.4 million shares of common stock pursuant to our share repurchase program, at an average cost of $11.70 per share, for an aggregate purchase price of $4.2 million.

Financial Summary

As of September 30, 2025, we had cash, cash equivalents and short-term investments of $36.1 million.

For the nine months ended September 30, 2025, our cash used in operations was $76.3 million and included a net loss for the nine months ended September 30, 2025 of $89.8 million.

We expect to receive an upfront cash payment, of $240.0 million upon Closing of the Transaction with Novo Nordisk, a portion of which will be applied to the full and immediate repayment of our $67.1 million Term Loan along with a related prepayment premium, certain expenses, and accrued and unpaid interest.

Repayment will result in termination of the Credit Agreement and the release in full of all liens and covenants thereunder including the covenant whereby we must maintain a minimum of $25.0 million of unrestricted cash, cash equivalents and short-term investments at all times.

As of March 31, 2026, we had cash, cash equivalents and short-term investments of $135.3 million.

For the three months ended March 31, 2026, our cash used in operations was $14.5 million.

See “Note 1 — Organization and Basis of Presentation, Liquidity and Capital Resources ” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q for further details.

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 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 closed on an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Rayner Surgical Inc.

(“Rayner”) for the sale of OMIDRIA and related business assets, which we recorded as an OMIDRIA contract asset on our condensed consolidated balance sheet.

The results of OMIDRIA activities, which includes royalties earned and the effect of any remeasurement adjustments, are classified as discontinued operations in our condensed consolidated statements of operations and comprehensive loss.

We currently earn royalties from Rayner on all U.S.

based net sales of OMIDRIA through December 31, 2031 at a royalty rate of 30%.

Our royalty rate would be reduced to 10% 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.

We are entitled to earn royalties until the expiration or termination of the last issued and unexpired U.S.

patent, which we expect to occur no earlier than 2035.

Pursuant to legislation enacted in late 2022, we also expect separate payment for OMIDRIA under Medicare Part B to extend until at least January 1, 2028.

We previously sold to DRI Healthcare Acquisition LP (“DRI”) our future U.S.

based OMIDRIA royalty receipts through December 31, 2031 which we record as an OMIDRIA royalty obligation on our condensed consolidated balance sheet.

based royalties 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 ex-U.S.

royalties through December 31, 2031 and royalties on global net sales of OMIDRIA after this date, including royalties on U.S.

OMIDRIA net sales.

Interest expense on the OMIDRIA royalty obligation is recorded as a component of continuing operations.

For further details, see “Note 2 – Significant Accounting Policies, Discontinued Operations and OMIDRIA Royalty Obligations ,” and “Note 8 — OMIDRIA Royalty Obligation” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q.

Results of Operations

Product Sales, Net

Distribution and sales of our only commercial product, YARTEMLEA, commenced in January 2026.

Product sales, net for the three months ended March 31, 2026 were $9.9 million, compared to no product revenue for the same period in the prior year.

Revenue in the current period reflects initial sales of YARTEMLEA to wholesalers in the U.S.

As this represents the first period of commercial sales, period-over-period comparisons are limited, and revenue mayfluctuate in future periods as we continue to expand patient access and physician adoption.

Product sales, net were as follows:

Three Months Ended

(In thousands)

Product sales, net

Gross-to-Net Deductions

We record YARTEMLEA product sales net of estimated chargebacks and distribution fees, or gross-to-net deductions.

Gross-to-net deductions are estimates based on contractual terms and expected utilization and require some judgment.

For the three months ended March 31, 2026, no chargebacks were recorded related to Medicaid claims.

As this represents the initial period of commercial sales, these estimates are preliminary and subject to change as additional information becomes available.

A summary of our gross-to-net related accruals for the three months ended March 31, 2026 is as follows:

Distribution Fees

(In Thousands)

Balance as of March 31, 2026

We record a provision for estimated chargebacks when YARTEMLEA product sales are recognized and reduce the accrual as payments are made or credits are granted.

Chargebacks represent the difference between the price we charge wholesalers and the contracted or statutorily required prices available to eligible purchasers under government programs, including our federal supply schedule agreement, and are estimated based on known pricing terms and expected utilization.

Distribution Fees

We pay our wholesalers a distribution fee for services they perform for us based on the dollar value of their purchases of YARTEMLEA.

We record a provision for these charges as a reduction to revenue at the time of sale to the wholesaler and make payments to our wholesalers based on contractual terms.

Cost of Product Sales

Cost of product sales is as follows:

Three Months Ended

(In thousands)

Cost of product sales

Cost of product sold for the period was low, primarily reflecting the sale of inventory manufactured prior to regulatory approval, for which the associated manufacturing costs were expensed as research and development in prior periods.

Accordingly, this inventory carries a low or no cost basis, resulting in lower cost of product sold and higher gross margin during the initial commercialization period.

Research and Development Expenses

7 unchanged sentences

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 European Union.

The following table illustrates our expenses associated with these activities:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Clinical research and development:

MASP-3 program - OMS906 (zaltenibart)

MASP-2 program - OMS721 (narsoplimab)

PDE7 program - (NIDA)

MASP-3 program - OMS906 (zaltenibart)

MASP-2 program - OMS1029 and other

5 unchanged sentences

Total research and development expenses

For the three months ended September 30, 2025, clinical research and development expenses decreased $6.2 million.

We began initiating clinical trial sites in our Phase 3 program for zaltenibart in PNH during the first quarter of 2025;

however, based on considerations of capital availability and the anticipated ramp up in spending on those trials, we determined in the second quarter of 2025 to pause this program temporarily in order to prioritize the use of our available capital to other programs.

Clinical research activity also decreased in the third quarter due to the coincidental wind down of several of our Phase 2 zaltenibart studies.

Additionally, we incurred non-recurring expenses related to the wind-down of our IgAN program in the prior year and consultancy charges related to BLA submission for narsoplimab in TA-TMA.

For the nine months ended September 30, 2025, clinical research and development expenses decreased $31.2 million primarily due to the inclusion in the prior year period of drug substance manufacturing expenses of $17.8 million for narsoplimab and $4.3 million for zaltenibart.

In addition, we incurred $4.7 million of expenses in the prior year period related to the wind-down of our narsoplimab IgAN program.

We expect research and development expenses in the fourth quarter of 2025 to be comparable to the third quarter of this year.

For the three months ended March 31, 2026, clinical research and development expenses decreased $7.2 million as compared to the prior year period as a result of reduced expenditures on OMS906 due to the sale of zaltenibart to Novo Nordisk.

Internal overhead and other expenses decreased $2.8 million as compared to the prior year period primarily due to Novo Nordisk reimbursing the Company for hours worked under the Transition Services Agreement and decreased employee compensation costs.

We expect research and development expenses in the second quarter of 2026 to be higher than in the first quarter of this year, driven primarily by increased investment in our YARTEMLEA and broader lectin pathway inhibitor programs as well as in our OncotoX -AML program, including costs associated with manufacturing and related activities, clinical development efforts, and regulatory support for our YARTEMLEA MAA in 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.

5 unchanged sentences

Selling, General and Administrative Expenses

Selling, general and administrative expenses are as follows:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

3 unchanged sentences

Total selling, general and administrative expenses

Total selling, general and administrative expenses, excluding stock-based compensation, decreased by $4.3 million for the nine months ended September 30, 2025, compared to the same period in the prior year.

The decrease was primarily due to a reduction in employee compensation expenses in the current year.

The $0.5 million and $1.3 million decrease in stock-based compensation for the three and nine months ended September 30, 2025, respectively, compared to the same periods in the prior year is due to the valuation and timing of the vesting of employee stock options.

We expect selling, general and administrative expenses in the fourth quarter of 2025 to be higher than those in the third quarter of this year, primarily due to increased marketing expenses associated with the anticipated launch of narsoplimab in TA-TMA, if approved by regulatory authorities.

Total selling, general and administrative expenses, excluding stock-based compensation, increased $2.6 million for the three months ended March 31, 2026, compared to the three months ended March 31, 2025, primarily due to the build-out of our U.S.

commercial organization, including the hiring of a sales force and increased marketing and market access activities in support of the YARTEMLEA launch.

The $0.3 million decrease in stock-based compensation for the three months ended March 31, 2026 compared to the same period in the prior year is due to the valuation and timing of the vesting of employee stock options.

We expect selling, general and administrative expenses in the second quarter of 2026 to be higher than in the first quarter of 2026, driven primarily by increased selling and marketing activities associated with YARTEMLEA.

Interest Expense

1 unchanged sentence

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

7 unchanged sentences

Contractual interest expense

Amortization of debt premium and issuance costs

Interest expense on Term Loan

Contractual interest expense

Amortization of debt discount and issuance costs

Interest expense on 2026 Notes

Contractual interest expense

Amortization of debt premium and issuance costs

Interest expense on Term Loan

Finance leases and other

Total interest expense, net of remeasurement adjustments and other

Total interest expense, net of remeasurement and other

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.

3 unchanged sentences

Debt discounts on the 2026 Notes and 2029 Notes are accretive whereas the premium on the Term Loan is deducted from contractual interest expense.

For the three months ended September 30, 2025, interest expense decreased $17.5 million compared to the same period in 2024.

The decrease primarily relates to $22.3 million of non-cash remeasurement costs on the OMIDRIA royalty obligation to reflect a change in forecasted OMIDRIA cash flows from Rayner.

Excluding the OMIDRIA royalty obligation and any non-cash amortization of debt discount, premium, or issuance costs, contractual interest expense increased $0.5 million primarily due to incurring a full quarter of interest expense on the 2029 Notes issued in May 2025 at a higher rate of interest than the 2026 Notes.

For the nine months ended September 30, 2025, interest expense decreased $31.2 million compared to the same period in 2024.

The decrease primarily relates to $32.6 million of non-cash remeasurement costs on the OMIDRIA royalty obligation to reflect a change in forecasted OMIDRIA cash flows from Rayner.

Excluding the OMIDRIA royalty obligation and any non-cash amortization of debt discount, premium, or issuance costs, contractual interest expense increased $1.9 million due to (i) incurring nine months of interest on our Term Loan compared to four months of interest in the prior year period as the Term Loan was issued in June 2024 and (ii) incurring interest on the 2029 Notes at a higher coupon rate of interest than the 2026 Notes for which they were exchanged.

For further information see “Note 6 — Debt” and “Note 8 – OMIDRIA Royalty Obligation” in the Notes to Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q.

We expect that interest expense for the fourth quarter of 2025 will be higher compared to the third quarter, under the assumption that there is no remeasurement adjustment to the OMIDRIA contract royalty obligation.

For the three months ended March 31, 2026, interest expense increased $2.2 million compared to the same period in 2025.

The increase primarily relates to incurring a full quarter of interest on our 2029 Notes, which were not yet issued in the same period in the prior year, and to a lesser extent a non-cash remeasurement of our OMIDRIA royalty obligation.

These increases are partiallyoffset by decreases in interest related to the remainder of our 2026 Notes, which were repaid in February 2026, and the Term Loan, which was repaid in November 2025.

For further information see “Note 6 — Debt” and “Note 8 – OMIDRIA Royalty Obligation” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q.

We expect interest expense for the second quarter of 2026 to be higher than in the first quarter of 2026, assuming no remeasurement adjustment to the OMIDRIA contract royalty obligation.

Interest and Other Income

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

Interest and other income

Interest and other income decreased $1.7 million and $6.0 million, respectively, for the three and nine months ended September 30, 2025 as compared to the same periods in 2024 primarily due to holding a lower average cash and investment balance than in the prior year periods.

We expect interest and other income for the fourth quarter of 2025 to be slightly higher compared to the third quarter of this year due to higher anticipated cash balances.

Loss on early extinguishment of 2026 convertible senior notes

Interest and other income increased $0.4 million for the three months ended March 31, 2026 as compared to the same period in 2025 primarily due to the receipt of $0.7 million of additional investment income as a result of holding higher average cash and investment balances than in the prior year period, partiallyoffset by decreased sublease income of $0.3 million for laboratory space.

We expect interest and other income for the second quarter of 2026 to be higher than in the first quarter of 2026.

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

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

Loss on early extinguishment of convertible senior notes

In May 2025, we exchanged $70.8 million principal amount of 2026 Notes for the same principal of 2029 Notes and entered into agreements to equitize $10.0 million of 2026 Notes, realizing a $3.0 million non-cash loss on extinguishment.

The extinguishment reflects marking-to-market the 2029 Notes and the expensing of capitalized debt issuance costs on the retired portion of the 2026 Notes.

Net loss on change in fair value of financial instruments

Net gain (loss) on change in fair value of financial instruments

Our embedded derivatives comprise call and put options related to our 2029 Notes and Term Loan.

As of March 31, 2026, the $73.1 million net gain on the embedded derivatives reflects marking to market the option of the holders of the 2029 Notes to convert their notes into shares of common stock, cash or a combination thereof.

As of March 31, 2026, we no longer have the derivative on our Term Loan as it was repaid on November 25, 2025.

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

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

Net loss on change in fair value of financial instruments

Our embedded derivatives comprise call and put options related to our 2029 Notes and Term Loan.

The $8.8 million increase in net loss for the three months ended September 30, 2025 reflects (i) a $7.1 million net liability increase in the fair value of our 2029 Notes embedded derivative reflecting the option of holders to convert their notes into shares of common stock, which is affected by an increase in our stock price, and (ii) a $1.7 million net liability change in our Term Loan embedded derivative reflecting a greater likelihood of a prepayment occurring due to signing of the APLA and the anticipated Closing of the Transaction with Novo Nordisk.

The $0.7 million increase in net loss for the nine months ended September 30, 2025 reflects a $1.8 million net liability change in our Term Loan embedded derivative, offset by a $0.8 million net liability decrease in our 2029 embedded derivative and a $0.3 million remeasurement of the share-settled liability.

Income tax expense

Income tax expense reflects income tax payments to state jurisdictions.

Discontinued operations and the OMIDRIA contract royalty asset

1 unchanged sentence

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2 unchanged sentences

Other income (loss), net

Ex-US royalties

Net income (loss) from discontinued operations, net of tax

Net income (loss) from discontinued operations decreased $14.6 million and $25.7 million, respectively, for the three and nine months ended September 30, 2025 due to remeasurement of the OMIDRIA contract royalty asset.

The decrease was primarily attributable to a remeasurement of our OMIDRIA contract royalty asset to reflect lower forecasted sales of OMIDRIA.

Income before income tax

Income tax benefit

Net income from discontinued operations, net of tax

Net income from discontinued operations increased $0.7 million for the three months ended March 31, 2026, primarily due to remeasurement of the OMIDRIA contract royalty asset in the prior year.

The following schedule presents a roll-forward of the OMIDRIA contract royalty asset (in thousands):

3 unchanged sentences

Remeasurement adjustments

OMIDRIA contract royalty asset at September 30, 2025

OMIDRIA contract royalty asset at March 31, 2026

Financial Condition – Liquidity and Capital Resources

As of September 30, 2025, we had cash, cash equivalents, and short-term investments of $36.1 million.

For the nine months ended September 30, 2025, our cash used in operations was $76.3 million and included a net loss for the period of $89.8 million.

Pursuant to a covenant in the Credit Agreement entered into on June 3, 2024, we must maintain $25.0 million of unrestricted cash, cash equivalents, and short-term investments at all times.

We have maintained a balance of unrestricted cash, cash equivalents, and short-term investments greater than $25.0 million and at no time during the quarter or through the date of issuance of these condensed consolidated financial statements have we been in violation of any of our debt covenants.

In recent years, Omeros has incurred net losses from continuing operations and negative cash flows from operations.

We will be entitled to receive an upfront cash payment of $240.0 million upon Closing of the Transaction with Novo Nordisk, which is expected to occur in the fourth quarter of 2025.

As such, the Closing will result in the mandatory prepayment of all outstanding obligations under our Credit Agreement and a portion of the proceeds will be applied at the Closing to fund full repayment of the $67.1 million outstanding principal amount of Term Loan, along with a 5.0% prepayment premium, certain expenses, and accrued and unpaid interest.

Repayment will result in termination of the Credit Agreement and the release in full of all liens and covenants thereunder.

On July 28, 2025, in a registered direct offering, we issued and sold to entities managed by Polar Asset Management Partners 5,365,853 shares of our common stock 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 the shares.

We received $20.3 million in cash proceeds net of offering expenses.

Further, we have a sales agreement pursuant to an at-the-market (“ATM”) equity offering facility through which we may, from time to time, offer and sell shares of our common stock equaling an aggregate amount of up to $150.0 million.

During the three and nine months ended September 30, 2025, we received $9.0 million and $15.3 million, respectively, of net proceeds from the sale of our common stock through the ATM facility and have received $3.6 million subsequent to September 30, 2025.

If the ATM facility is needed but inaccessible, we are not able to close the Transaction with Novo Nordisk when anticipated, or we are not able to obtain debt and/or royalty-related financing and/or partnering funding in connection with a near-term regulatory approval of narsoplimab, it would have a significant negative impact on our financial condition.

For purposes of determining available capital resources, any future royalty and/or milestone receipts are excluded.

We have taken steps to manage our operating expenses and reduce our projected cash requirements by delaying clinical trials and reducing selected research and development efforts.

Should it be necessary, we may determine to further reduce or delay these or other aspects of our operations and/or implement other restructuring activities.

Furthermore, as we currently do not have an ongoing source of revenue sufficient to cover our operating costs, should the need arise to raise further capital for our operations, we may pursue public and private offerings of our equity securities, debt financings, 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.

The conditions described above, including the need to raise additional capital, when evaluated in accordance with the relevant accounting literature, raise substantial doubt with respect to our ability to meet our obligations through one year from the issuance of the Company's condensed consolidated financial statements.

Our ability to continue as a going concern will require us to generate positive cash flow from operations, obtain additional financing, enter into strategic alliances, and/or sell assets, and this determination is made without considering any such potential future activities.

The accompanying condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from uncertainty related to our ability to continue as a going concern or to the expected Closing of the Transaction with Novo Nordisk.

As of March 31, 2026, we had cash, cash equivalents, and short-term investments of $135.3 million.

For the three months ended March 31, 2026, our cash used in operations was $14.5 million.

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

Omeros expects that it will be able to fund more than 12 months of operations from the date the financial statements are issued, utilizing our current cash, cash equivalents, and short-term investments, along with funds we expect to receive from commercial sales of YARTEMLEA.

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 an ATM facility agreement under which we have the capability to sell shares of our common stock, from time to time, in an ATM equity offering through which we may offer and sell shares of our common stock equaling an aggregate amount of up to $150.0 million.

Cash Flow Data

Nine Months Ended

September 30,

Three Months Ended

(In thousands)

5 unchanged sentences

Operating Activities .

Net cash used in operating activities for the nine months ended September 30, 2025 decreased by $43.6 million as compared to the same period in 2024, driven primarily by a $35.7 million decrease in net loss and a $17.4 million increase in accounts payable, partially offset by $9.8 million of non-cash items, which is primarily comprised of remeasurement adjustments on forecasted OMIDRIA royalties affecting both the OMIDRIA contract royalty asset and OMIDRIA royalty obligation.

Net cash used in operating activities for the three months ended March 31, 2026 decreased $21.3 million as compared to the same period in 2025, driven primarily by a $89.5 million change in net income from a net loss in the prior year period, partiallyoffset by a $73.1 million non-cash remeasurement of our 2029 Notes embedded derivative.

Other changes related to a $4.1 million reduction in accounts payable and accrued expenses.

Investing Activities .

2 unchanged sentences

As we manage our usage with respect to total cash, cash equivalents, and short-term investments, we do not consider fluctuations in cash flows from investing activities to be important to the understanding of our liquidity and capital resources.

Net cash provided by investing activities during the nine months ended September 30, 2025 increased by $5.7 million, reflecting the timing of purchase of investments from proceeds received on maturities and sales.

Net cash provided by investing activities during the three months ended March 31, 2026 decreased $9.8 million, reflecting the timing of purchase of investments from proceeds received on maturities and sales.

Financing Activities .

Net cash provided by financing activities for the nine months ended September 30, 2025 decreased by $44.7 million, primarily due to the change in financing activities between the current year and the prior year.

In the current year, we received proceeds from our registered direct offering from Polar of $20.3 million and ATM proceeds of $15.3 million.

In the prior year, we received $115.5 million in cash from DRI related to the sale of expanded OMIDRIA royalties in February 2024, which was partially offset by repurchases of $21.2 million in aggregate principal amount of our 2026 Notes and $11.9 million of shares of our common stock.

Net cash used in financing activities for the three months ended March 31, 2026 increased $20.1 million compared to the same period in the prior year primarily due to the repayment of $17.1 million in aggregate principal amount of our 2026 Notes at maturity in February 2026 and the repurchase of $4.2 million of our common stock under our share repurchase program during the three months ended March 31, 2026.

Contractual Obligations and Commitments

4 unchanged sentences

Our lease for our office and laboratory space ends in November 2027.

We have two options to extend the lease term by five years each.

We have two options to extend the lease term, each by five years.

In addition, we carry various finance lease obligations for laboratory and office equipment.

As of September 30, 2025, the remaining aggregate non-cancelable rent payable under the initial term of the lease, excluding common area maintenance and related operating expenses, is $15.1 million.

As of March 31, 2026, the remaining aggregate non-cancelable rent payable under the initial term of the lease, excluding common area maintenance and related operating expenses, is $11.1 million.

Convertible Senior Notes and Long-Term Debt

5 unchanged sentences

Critical Accounting Policies and Significant Judgments and Estimates

There have not been any material changes in our critical accounting policies and significant judgments and estimates as disclosed in Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in our Annual Report on Form 10-K for the year ended December 31, 2024, which was filed with the SEC on March 31, 2025 except as what we have disclosed in the notes to our financial statements regarding embedded derivatives.

For further details see “Note 2 — Significant Accounting Policies” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q.

The preparation of our condensed consolidated financial statements in conformity with U.S.

GAAP requires management to make estimates, judgments and assumptions that affect the amounts reported in the financial statements and accompanying notes.

We base our estimates on historical experience, current conditions and other factors we believe to be reasonable under the circumstances;

however, actual results could differ materially from those estimates.

We consider an accounting policy to be critical if it requires significant judgment and has a material impact on our financial condition and results of operations.

Revenue Recognition

We recognize revenue from product sales when title of the product is transferred to our customers, which generally occurs upon delivery to wholesalers.

At that point, our performance obligations are satisfied.

Activities performed by wholesalers after delivery are not considered separate performance obligations.

We generally record revenue from product sales when the product is delivered to our wholesalers and title for the product is transferred, upon which we have satisfied our performance obligations.

Fulfillment activities by the wholesalers are not considered to be a separate performance obligation.

Product revenue is recorded net of variable consideration, including wholesaler distribution fees, chargebacks, returns and discounts.

We estimate variable consideration using the expected value approach.

This estimate is based on several factors, including:

historical return rates, expiration date by product, estimated levels of inventory in the wholesale channel.

Chargebacks represent discounts provided to eligible covered entities under government programs, including the 340B Drug Pricing Program and the Medicaid Drug Rebate Program.

In addition, we are subject to pricing obligations under our Federal Supply Schedule agreement with the U.S.

government (the “FSS Agreement”), which establishes maximum prices for sales to certain federal agencies and may give rise to additional discounts and rebates.

Chargebacks are recorded as a reduction of gross product revenue at the time of sale.

We also maintain programs that may give rise to similar deductions, including patient co-pay assistance programs.

For the three months ended March 31, 2026, chargebacks were primarily attributable to discounts under the 340B Drug Pricing Program, and no material reductions to gross product revenue were recorded for other programs.

We will continue to evaluate utilization of these programs and recognize the related reductions to revenue in the period in which they occur.

For further details of our other Critical Accounting Policies, see “Note 2 — Significant Accounting Policies” in the Notes to the Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q and Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in our Annual Report on Form 10-K for the year ended December 31, 2025, which was filed with the SEC on March 31, 2026.

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-Q

Item 1. Financial Statements