(OMER) Omidria™ Granted Pass-Through Reimbursement Status from CMS

— Unique Billing Code Allows Separate Payment for Omidria —

SEATTLE, Oct. 30, 2014  — Omeros Corporation (NASDAQ: OMER) announced today that it has received transitional pass-through status for its lead product Omidria^™ (phenylephrine and ketorolac injection) 1%/0.3% from the Center for Medicare & Medicaid Services (CMS), the federal agency that administers the Medicare program. Approved earlier this year by the U.S. Food and Drug Administration (FDA) for use during cataract surgery or intraocular lens replacement (ILR), Omidria is the only FDA-approved product for intraocular administration that prevents intraoperative miosis (pupil constriction) and reduces postoperative pain, providing consistent and predictable management of these problems for ophthalmic surgeons and their patients. A large and growing market, cataract and other ILR procedures are among the most common surgical procedures performed in the U.S. with approximately four million expected in 2015.

Transitional pass-through status will allow ambulatory surgery centers and other outpatient facilities to bill Medicare and other insurance providers for Omidria using a temporary Healthcare Common Procedure Coding System (HCPCS) code unique to Omidria. Pass‑through status allows for separate payment for new drugs and other medical technologies that meet specific clinical-value and cost requirements. Pass‑through remains in effect for a period of two to three years, after which time CMS and other insurance providers make a new reimbursement determination. Pass‑through status for Omidria will become effective on January 1, 2015, and reimbursement will be based on the product’s wholesale acquisition cost of between $400 and $500 per single-use vial.

“We are pleased with CMS’s decision to grant pass-through for Omidria,” said Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. “Pass-through status should streamline the billing and reimbursement process for facilities that use Omidria and could accelerate adoption of the product across cataract and other intraocular lens procedures. Coincident with this new clarity on reimbursement, our commercial team is in the process of adding the second wave of sales representatives, and we plan to launch Omidria no later than early 2015.”

About Omidria^™
Omeros’ PharmacoSurgery^® product Omidria^™ (pronounced oh-MID-ree-uh) is a proprietary combination of the mydriatic (pupil-dilating) agent phenylephrine and the anti-inflammatory agent ketorolac, which was developed for use during cataract or other intraocular lens replacement (ILR) surgery. The FDA has approved Omidria (phenylephrine and ketorolac injection) 1%/0.3% for use during cataract surgery or ILR to maintain pupil size by preventing intraoperative miosis (pupil constriction) and to reduce postoperative pain. The European Medicines Agency (EMA) is currently reviewing the Marketing Authorization Application (MAA) for Omidria.

Important Risk Information for Omidria^™

Systemic exposure of phenylephrine may cause elevations in blood pressure. In clinical trials, the most common reported ocular adverse reactions at two to 24 percent are eye irritation, posterior capsule opacification, increased intraocular pressure, and anterior chamber inflammation. Omidria^™ must be diluted prior to use. Omidria is not approved for use in children.

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 no later than early 2015. 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.

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,” “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.