Omeros Corporation Reports Second Quarter 2014 Financial Results FDA Approval of Omidria Received on

Omeros Corporation Reports Second Quarter 2014 Financial Results

FDA Approval of Omidria Received on May 30, 2014

Seattle, WA August 11, 2014 Omeros Corporation (NASDAQ: OMER), a biopharmaceutical company committed to discovering, developing and

commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system, today announced financial results and highlights for the

second quarter of 2014, which include:

Obtaining U.S. marketing approval for Omidria is a tremendous accomplishment for Omeros, said Gregory A. Demopulos, M.D., chairman and chief

executive officer of Omeros. It marks a pivotal point in our transition to a commercial company, and we are continuing preparations for a planned U.S. product launch in the fourth quarter of 2014. In that same time frame, we also expect to

receive a decision on the EU marketing application for Omidria. While we remain focused on the market launch of Omidria, we continue to advance the rest of our pipeline, including our MASP-2 inhibitor OMS721 and PDE10 inhibitor OMS824 Phase 2

clinical programs in patients with TMAs and Huntington s, respectively. We expect preliminary data from each of those Phase 2 trials later this year.

Second Quarter and Recent Highlights

For the quarter ended June 30,

2014, Omeros reported a net loss of $18.0 million, or $0.53 per share. This compares to a net loss of $13.6 million or $0.48 per share, for the same period in 2013. Noncash expenses were $2.5 million ($0.07 per share) for the quarter ended

June 30, 2014 and $2.2 million ($0.08 per share) for the same period in 2013.

Operating expenses for the three months ended June 30, 2014 were

$17.3 million compared to $13.3 million for the same period in 2013. The increase was primarily related preparing for the U.S. commercial launch of Omidria later this year and to manufacturing of material and clinical costs associated with the Phase

2 clinical trials evaluating OMS721 in TMAs and OMS824 in Huntington s disease.

Revenue for the quarter ended June 30, 2014 was $45,000

compared to $140,000 for the same period in 2013. This decrease was due to a reduction of activity on NIH grant projects, which resulted in lower revenue being recognized.

At June 30, 2014, Omeros had cash and cash equivalents and short-term investments of $37.5 million.

About Omeros Corporation

Omeros is a biopharmaceutical

company committed to discovering, developing and commercializing small-molecule and protein therapeutics for large-market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system. Derived from

its proprietary PharmacoSurgery platform, the Company s first drug product, Omidria (phenylephrine and ketorolac injection) 1%/0.3%, has been approved by the FDA for use during

cataract surgery or intraocular lens replacement (ILR) to maintain pupil size by preventing intraoperative miosis (pupil constriction) and to reduce postoperative ocular pain. Omeros is completing preparations for a planned U.S. product launch in

the fourth quarter of 2014. Omidria is currently under review for marketing approval by the European Medicines Agency. Omeros also has six clinical-stage development programs focused on complement-related thrombotic microangiopathies,

Huntington s disease, schizophrenia, and cognitive impairment; on addictive and compulsive disorders; and on preventing problems associated with surgical procedures. Omeros also has a proprietary GPCR platform, which is making available an

unprecedented number of new GPCR drug targets and corresponding compounds to the pharmaceutical industry for drug development.

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, look forward to, may, plan,

potential, predict, project, should, will, would and similar expressions. 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, risks associated with

effectiveness of Omidria sales and marketing efforts, Omidria market acceptance, product pricing and

reimbursement, Omeros ability to obtain regulatory approval for its Marketing Authorization Application in the EU for the commercialization of Omidria, Omeros unproven preclinical and

clinical development activities, regulatory oversight, product commercialization, intellectual property claims, competitive developments, litigation, and 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 August 11, 2014. 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, 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