Company Description
Omeros Corporation (NASDAQ: OMER) is a biopharmaceutical company focused on discovering, developing, and commercializing first-in-class small-molecule and protein therapeutics for both large-market and orphan indications. According to the company’s disclosures, its programs concentrate on immunologic disorders, with particular emphasis on complement-mediated diseases, cancers, and addictive or compulsive disorders. Omeros’ work spans clinical-stage development through to commercialization, with a growing portfolio of monoclonal antibodies and small molecules targeting key components of the complement system and other disease pathways.
Core focus on complement-mediated diseases
A central pillar of Omeros’ strategy is modulation of the complement system, a part of innate immunity. The company has developed drug candidates that selectively inhibit different complement pathways by targeting mannan-binding lectin-associated serine proteases (MASPs). Its lead lectin pathway inhibitor, YARTEMLEA (narsoplimab-wuug), is described by Omeros as a fully human monoclonal antibody that inhibits MASP-2, the effector enzyme of the lectin pathway of complement. By blocking MASP-2, YARTEMLEA inhibits lectin pathway activation while preserving classical and alternative pathway activity, which the company notes is important for adaptive immune responses.
YARTEMLEA is FDA-approved for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) in adults and in children two years of age and older. Omeros states that YARTEMLEA is the first and only approved inhibitor of the lectin pathway of complement and the first and only approved therapy for TA-TMA. The company has also submitted a marketing authorization application for YARTEMLEA in TA-TMA to the European Medicines Agency, with review underway.
TA-TMA and Omeros’ role
Omeros describes TA-TMA as a severe and often-fatal complication of hematopoietic stem cell transplantation in adults and children. It is driven by systemic endothelial injury triggered by conditioning regimens, immunosuppressants, infection, graft-versus-host disease, and other transplant-related factors, with activation of the lectin pathway of complement playing a central role in disease pathogenesis. The company cites published data indicating that TA-TMA can develop in a substantial proportion of allogeneic transplant recipients and that mortality in severe cases can exceed 90 percent, with survivors often facing long-term renal complications.
In its communications, Omeros highlights clinical data for YARTEMLEA in TA-TMA from a pivotal single-arm study and a global expanded access program. These data include complete response rates based on laboratory and clinical criteria and survival outcomes at defined time points after TA-TMA diagnosis. The company also references peer-reviewed publications that compare survival in high-risk TA-TMA patients treated with narsoplimab to external control cohorts managed with supportive care and off-label therapies.
Pipeline beyond YARTEMLEA
Beyond YARTEMLEA, Omeros reports a pipeline of complement-targeted and non-complement programs:
- OMS1029: a long-acting MASP-2 inhibitor that has successfully completed Phase 1 clinical trials, positioned as a follow-on lectin pathway program.
- Zaltenibart (OMS906): a humanized monoclonal antibody targeting MASP-3, the key and most upstream activator of the alternative pathway of complement. Omeros describes zaltenibart as a first-in-class, late-stage clinical candidate with potential applications in paroxysmal nocturnal hemoglobinuria (PNH), renal diseases such as immunoglobulin A nephropathy (IgAN), C3 glomerulopathy, atypical hemolytic uremic syndrome, and other immune and complement-driven disorders.
- OMS527: a phosphodiesterase 7 (PDE7) inhibitor in clinical development for cocaine use disorder, fully funded by the U.S. National Institute on Drug Abuse (NIDA). The company notes that preclinical cocaine interaction/toxicology studies have been completed with no safety findings in support of an in-patient clinical study.
- Oncology programs: Omeros is advancing molecular and cellular oncology programs, including its OncotoX-AML biologics program for acute myeloid leukemia (AML) and a Targeted Complement Activating Therapy (T-CAT) platform aimed at multidrug-resistant organisms and other pathogens. The company reports preclinical data suggesting broad application of OncotoX-AML across AML genetic subtypes and activity of T-CAT constructs against multiple pathogen classes.
In an asset purchase and license agreement with Novo Nordisk, Omeros granted Novo Nordisk exclusive global rights to zaltenibart and certain related antibodies and products. Under this agreement, Omeros is eligible for an upfront cash payment, additional near-term milestone payments, further development, approval and sales-based milestones, and tiered royalties on net sales. The company retains rights to its MASP-3 small-molecule program and certain grandfathered MASP-3 antibodies under defined conditions.
Business model and revenue sources
Omeros’ business model, as described in its news releases and SEC filings, combines internal drug discovery and development with commercialization of approved products and partnering arrangements. Revenue and funding sources referenced by the company include:
- Commercialization of its complement inhibitor for TA-TMA in the United States following FDA approval of YARTEMLEA.
- Royalties from OMIDRIA on U.S. net sales, remitted to a third-party counterparty under a royalty agreement, with Omeros reporting earned royalties as part of its financial results.
- Non-dilutive funding through grants, such as the multi-year NIDA grant supporting OMS527 development.
- Upfront and milestone payments and potential royalties from licensing and asset sale transactions, exemplified by the zaltenibart agreement with Novo Nordisk.
- Equity financings, including registered direct offerings and at-the-market equity programs disclosed in SEC filings.
Regulatory and clinical development activities
Omeros regularly reports on its regulatory interactions and clinical development milestones. For YARTEMLEA (narsoplimab-wuug), the company describes the FDA approval for TA-TMA and the ongoing review of a marketing authorization application by the European Medicines Agency. For other programs, Omeros provides status updates such as completion of Phase 1 trials for OMS1029, late-stage development of zaltenibart in PNH and C3 glomerulopathy before the Novo Nordisk transaction, and IND-enabling work for OncotoX-AML.
The company also notes that YARTEMLEA has received breakthrough therapy and orphan drug designations from the FDA for TA-TMA, and that the EMA has granted orphan drug designation in hematopoietic stem-cell transplantation. Narsoplimab has similarly received orphan drug designation for TA-TMA and related indications, according to Omeros’ communications.
Capital markets and corporate profile
Omeros Corporation is incorporated in Washington and files periodic and current reports with the U.S. Securities and Exchange Commission under Commission File Number 001-34475. Its common stock trades on the Nasdaq market under the ticker symbol OMER. The company has used registered direct offerings, at-the-market equity facilities, convertible senior notes, and secured term loans as part of its capital structure, and has disclosed transactions to refinance or repay debt and to strengthen its balance sheet.
In its shareholder communications, Omeros emphasizes the potential of its first-in-class pipeline programs in complement biology, addiction medicine, oncology, and infectious disease. The company positions its complement inhibitors, including YARTEMLEA, OMS1029, and zaltenibart (now partnered with Novo Nordisk), as differentiated approaches targeting distinct components of the complement cascade while aiming to preserve protective immune functions.
Key themes for OMER stock research
Investors analyzing OMER stock commonly focus on:
- The commercial uptake and reimbursement landscape for YARTEMLEA in TA-TMA.
- Regulatory outcomes and potential geographic expansion for YARTEMLEA beyond the United States.
- Progress in OMS1029, OMS527, and oncology and T-CAT programs through clinical and regulatory milestones.
- Execution of the Novo Nordisk partnership for zaltenibart and the timing and magnitude of potential milestone and royalty streams.
- The company’s financing activities, royalty arrangements, and overall liquidity as described in its SEC filings.
Frequently asked questions about Omeros Corporation
Stock Performance
Omeros (OMER) stock last traded at $10.90. Over the past 12 months, the stock has gained 36.1%. At a market capitalization of $772.8M, OMER is classified as a small-cap stock with approximately 72.0M shares outstanding.
Latest News
Omeros has 10 recent news articles, with the latest published 4 days ago. Of the recent coverage, 7 articles coincided with positive price movement and 2 with negative movement. Key topics include earnings, earnings date, conferences, fda approval. View all OMER news →
SEC Filings
Omeros has filed 5 recent SEC filings, including 1 Form 4, 1 Form 10-K, 1 Form 8-K, 1 Form SCHEDULE 13G/A. The most recent filing was submitted on March 31, 2026. SEC filings provide transparency into a company's financial condition, material events, and regulatory compliance. View all OMER SEC filings →
Insider Radar
Insider selling at Omeros over the past 90 days can reflect routine portfolio management, scheduled trading plans (Rule 10b5-1), tax planning, or compensation-related dispositions rather than a directional view on the stock.
Financial Highlights
Omeros generated $900K in revenue over the trailing twelve months, operating income reached -$122.8M (-13644.0% operating margin), and net income was -$3.4M, reflecting a -372.2% net profit margin. Diluted earnings per share stood at $-1.88. The company generated -$116.1M in operating cash flow. With a current ratio of 2.76, the balance sheet reflects a strong liquidity position.
Upcoming Events
EMA decision window
EMA marketing authorization decision
Data for BLA submission
OncotoX-AML first-in-human trial
New notes maturity
Omeros has 5 upcoming scheduled events. The next event, "EMA decision window", is scheduled for May 1, 2026 (in 26 days). 1 of the upcoming events are financial in nature, such as earnings calls or quarterly results. Investors can track these dates to stay informed about potential catalysts that may affect the OMER stock price.
Short Interest History
Short interest in Omeros (OMER) currently stands at 17.3 million shares, up 0.1% from the previous reporting period, representing 25.1% of the float. Over the past 12 months, short interest has increased by 61.7%. This high level of short interest suggests significant bearish sentiment among traders. With 22.2 days to cover, it would take significant time for short sellers to close their positions based on average trading volume.
Days to Cover History
Days to cover for Omeros (OMER) currently stands at 22.2 days, up 25.5% from the previous period. This elevated days-to-cover ratio indicates it would take over two weeks of average trading volume for short sellers to exit their positions, suggesting potential for a short squeeze if positive news emerges. The days to cover has increased 149.8% over the past year, indicating either rising short interest or declining trading volume. The ratio has shown significant volatility over the period, ranging from 1.1 to 22.2 days.
OMER Company Profile & Sector Positioning
Omeros (OMER) operates in the Biotechnology industry within the broader Pharmaceutical Preparations sector and is listed on the NASDAQ.
Investors comparing OMER often look at related companies in the same sector, including Foghorn Therapeutics Inc. (FHTX), Capricor Therapeutics Inc (CAPR), Lineage Cell The (LCTX), Alector (ALEC), and Mereo Biopharma (MREO). Comparing financial metrics, valuation ratios, and stock performance across these peers can help investors evaluate OMER's relative position within its industry.