Omeros Corporation Reports Third Quarter 2012 Financial Results Seattle, WA

Omeros Corporation Reports Third Quarter 2012 Financial Results

Seattle, WA November 9, 2012 Omeros Corporation (NASDAQ: OMER), a clinical-stage biopharmaceutical company committed to

discovering, developing and commercializing products targeting inflammation, coagulopathies and disorders of the central nervous system, today announced its financial results for the third quarter of 2012.

expenses for the quarter ended September 30, 2012 were $14.5 million compared to $7.2 million for the same period in 2011. The increase in operating expenses primarily relates to a one-time litigation settlement payment of $3.95 million, which

our insurance company has agreed to reimburse to us subject to a reservation of rights, increased Phase 3 clinical trial expenses for OMS302 and increased employee expenses, partially offset by a decrease in expenses in connection with preclinical

work for other programs. Given that the $3.95 million that Omeros insurer has agreed to reimburse had not been received by Omeros as of September 30, 2012, that amount is not included in operating expenses for the 2012 period. For the

quarter ended September 30, 2012, Omeros reported a net loss of $13.3 million, or $0.51 per share, compared to a net loss of $6.5 million, or $0.29 per share, for the same period in 2011. At September 30, 2012, Omeros had cash, cash

equivalents and short-term investments of $30.6 million.

Now with positive results from both of our two pivotal Phase 3 clinical trials

evaluating OMS302, Omeros is becoming a commercial company, said Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. We are working to file an NDA in the first quarter of 2013 followed by an MAA in mid-year, and

we look forward to releasing data from two more clinical programs before year-end our Phase 3 meniscectomy and our Phase 1 PDE10 programs. Our clinical pipeline is expanding, and as many as three additional programs could enter the clinic in

2013. We continue to execute on our strategy of creating multiple opportunities for success.

Third Quarter and Recent Highlights

About Omeros Corporation

Omeros is a clinical-stage biopharmaceutical company committed to

discovering, developing and commercializing products targeting inflammation, coagulopathies and disorders of the central nervous system. The Company s most clinically advanced product candidates are derived from its proprietary

PharmacoSurgery platform designed to improve clinical outcomes of patients undergoing a wide range of surgical and medical procedures. Omeros has four ongoing clinical development programs. Omeros may also have the near-term capability,

through its GPCR program, to add a large number of new drug targets and their corresponding compounds to the market. Behind its clinical candidates and GPCR platform, Omeros is building a diverse pipeline of protein and small-molecule preclinical

programs targeting inflammation, coagulopathies and central nervous system disorders.

Forward-Looking Statements

This press release contains forward-looking statements as defined within the Private Securities Litigation Reform Act of 1995, which are subject to the

safe harbor created by those sections. These statements include, but are not limited to, Omeros expectations regarding when it will submit an NDA and MAA for OMS302; when sales may commence for OMS302; when it will announce the

results from its Phase 3 OMS103HP and Phase 1 PDE10 clinical trials; the number of its programs that will enter the clinic in 2013; and that Omeros may have capability, through its GPCR program, to add a large number of new drug targets and their

corresponding compounds to the market. Forward-looking statements 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, the risks, uncertainties and other factors described under the heading Risk Factors in the Company s

Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 9, 2012. 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 publicly, even if new information becomes available in the future.

Jennifer Cook Williams

Cook Williams Communications, Inc.

Investor and Media Relations

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except share and per share data)

CONSOLIDATED BALANCE SHEET DATA