Omeros Corporation Reports Third Quarter 2021 Financial Results - Conference Call Today at 4:30 p.m. ET - SEATTLE, WA

Omeros Corporation Reports Third Quarter 2021 Financial Results

- Conference Call Today at 4:30 p.m. ET -

SEATTLE, WA - November 9, 2021 - Omeros Corporation (Nasdaq: OMER), a commercial-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, immunologic diseases (e.g., complement-mediated diseases and cancers) and central nervous system disorders, today announced recent highlights and developments as well as financial results for the third quarter ended September 30, 2021, which include:

"With CMS reconfirming separate payment for OMIDRIA in the ASC setting, Omeros, together with cataract surgeons and facility administrators, is appreciative and confident that patients will continue to be able to access OMIDRIA, improving surgical outcomes," said Gregory A. Demopulos, M.D., Omeros' chairman and chief executive officer. "This is reflected in continued sales growth, with an increasing percentage of Medicare Advantage and commercial payers also recognizing the benefits of the drug and appropriately reimbursing for its use. The increasing OMIDRIA revenues are important as we focus our resources on our complement programs, primarily to achieve FDA approval of the narsoplimab BLA in HSCT-TMA and to drive the other high-priority components of our complement franchise - the Phase 3 trial of narsoplimab in IgA nephropathy and our MASP-3 inhibitor OMS906, which we plan to accelerate from a Phase 1 trial in healthy subjects to assessing the drug in PNH patients. We expect that our portfolio of commercial and development programs will continue to advance throughout 2022, and we look forward to capitalizing on the opportunities that the coming year holds."

Third Quarter and Recent Developments

Using the same analytical approach adopted by other companies* to determine the impact of proteinuria reduction on long-term risk of need for dialysis, the unprecedented 64.4 percent reduction in proteinuria that was seen in the Phase 2 narsoplimab-treated patients is predicted to delay progression to renal dialysis by more than 41.6 years compared to standard of care, a substantially longer projected delay to need for dialysis than has been reported for any other drug in development for the treatment of renal disease.

The second manuscript further examines the finding that lectin pathway hyperactivation severely impairs the classical complement activation pathway, which critically supports the infection-fighting adaptive immune response. A substantial incidence of life-threatening secondary infections occur in severe COVID-19. The data suggest that, by blocking the lectin pathway, narsoplimab could allow recovery of classical pathway functional activity and protect against infection by maintaining the complement-dependent antimicrobial defense of adaptive immunity in severe COVID-19 patients.

For the third quarter of 2021, OMIDRIA revenues were $30.0 million compared to $28.8 million for the second quarter, an increase of $1.2 million or 4.1 percent.

Total costs and expenses for the third quarter of 2021 were $48.3 million compared to $52.8 million for the preceding quarter. The decrease in the third quarter was primarily due to reduced preclinical research and development costs.

For the three months ended September 30, 2021, Omeros reported a net loss of $22.7 million, or $0.36 per share, which included non-cash expenses of $6.4 million, or $0.10 per share. This compares to a net loss in the previous quarter of $28.6 million, or $0.46 per share, which included non-cash expenses of $3.9 million, or $0.06 per share.

As of September 30, 2021, the company had $50.4 million of cash, cash equivalents and short-term investments. The company also has a line of credit, which permits borrowing up to the lesser of $50 million or 85 percent of eligible accounts receivable, less certain reserves. Omeros also has an "at the market" program in place that allows the company to sell, from time to time, up to $150 million of its common stock.

Conference Call Details

To access the live conference call via phone, please dial (844) 831-4029 from the United States and Canada or (920) 663-6278 internationally. The participant passcode is 7744465. A telephone replay will be available for one week following the call and may be accessed by dialing (855) 859-2056 from the United States and Canada or (404) 537-3406 internationally. The replay passcode is 7744465.

To access the live or subsequently archived webcast of the conference call on the internet, go to the company's website at

https://investor.omeros.com/upcoming-events.

*Carroll K. et al., Estimating Delay in Time to ESKD for Treatment Effects on Proteinuria in IgA Nephropathy and FSGS. ERA-EDTA 2021, Oral Presentation; and Calliditas Therapeutics AB, April 2019, Investor Day Webinar.

About Omeros Corporation

Omeros is a commercial-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market and orphan indications targeting inflammation, immunologic diseases (e.g., complement-mediated diseases and cancers) and central nervous system disorders. Its commercial product OMIDRIA (phenylephrine and ketorolac intraocular solution) 1%/0.3% continues to gain market share in cataract surgery. Omeros' lead MASP-2 inhibitor narsoplimab targets the lectin pathway of complement and is the subject of a biologics license application pending before FDA for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy. Narsoplimab is also in multiple late-stage clinical development programs focused on other complement-mediated disorders, including IgA nephropathy, atypical hemolytic uremic syndrome and COVID-19. OMS906, Omeros' inhibitor of MASP-3, the key activator of the alternative pathway of complement, is in a Phase 1 clinical trial, and the company's PDE7 inhibitor program OMS527, targeting addiction and movement disorders, has successfully completed a Phase 1 trial. Omeros' pipeline holds a diverse group of preclinical programs including a proprietary-asset-enabled antibody-generating technology and a proprietary GPCR platform through which it controls 54 GPCR drug targets and their corresponding compounds. One of these novel targets, GPR174, modulates a new cancer immunity axis recently discovered by Omeros, and the company is advancing GPR174-targeting antibodies and small-molecule inhibitors. Omeros' immune-oncology portfolio also includes a novel cell therapy platform designed to markedly improve response rates for patients receiving CAR-T or adoptive tumor-infiltrating T-cell therapies for liquid or solid tumors. For more information about Omeros and its programs, visit www.omeros.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, which are subject to the "safe harbor" created by those sections for such statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as "anticipate," "believe," "could," "estimate," "expect," "goal," "intend," "likely," "look forward to," "may," "objective," "plan," "potential," "predict," "project," "should," "slate," "target," "will," "would" and similar expressions and variations thereof. Forward-looking statements, including expectations with regard to interactions and communications with FDA and Omeros' pursuit of regulatory approval for narsoplimab in HSCT-TMA, are based on management's beliefs and assumptions and on information available to management only as of the date of this press release. Omeros' actual results could differ materially from those anticipated in these forward-looking statements for many reasons, including, without limitation, risks associated with product commercialization and commercial operations, unproven preclinical and clinical development activities, the impact of COVID-19 on our business, financial condition and results of operations, regulatory processes and oversight, challenges associated with manufacture or supply of our investigational or commercial products, changes in reimbursement and payment policies by government and commercial payers or the application of such policies, intellectual property claims, competitive developments, litigation, and the risks, uncertainties and other factors described under the heading "Risk Factors" in the company's Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 1, 2021. Given these risks, uncertainties and other factors, you should not place undue reliance on these forward-looking statements, and the company assumes no obligation to update these forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law.

Jennifer Cook Williams

Cook Williams Communications, Inc.

Investor and Media Relations

UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except share and per share data)

UNAUDITED CONSOLIDATED BALANCE SHEET DATA