Omeros (OMER) Reports Phase 2 Data Showing Multiple Clinical Benefits

SEATTLE, March 31 /PRNewswire-FirstCall/ — Omeros Corporation (Nasdaq: OMER) today announced that a Phase 2 clinical trial of OMS103HP, its PharmacoSurgery™ product candidate for arthroscopy, demonstrated that patients treated with OMS103HP during arthroscopic knee meniscectomy surgery achieved statistically significant clinical benefits.  OMS103HP is an investigational drug product that is added to arthroscopic irrigation solution and is designed to improve postoperative joint function and motion and reduce postoperative pain.

The Phase 2 clinical trial was a multicenter, randomized, double-blind, vehicle-controlled study. Of the 161 patients who were enrolled and treated, 143 patients met the predetermined surgical criteria and were included in the data analysis (71 OMS103HP and 72 vehicle). There were no important differences in demographic characteristics between the two treatment groups.

This study has shown that OMS103HP provides greater efficacy than vehicle as measured by visual analog scale (VAS) pain scores, passive knee flexion and patient reported functional scores using the Knee Injury and Osteoarthritis Outcome Score (KOOS).  The patient reported outcomes showed a sustained benefit through postoperative Day 90. OMS103HP was well tolerated, and adverse events were more frequent in the vehicle dose group.

Pain scores in the immediate 24-hour period and up to seven days postoperatively were measured using a validated, 100-point, VAS. Range of motion assessments were made at baseline and day seven postoperatively. The protocol was amended to collect patient self reports using the KOOS, which consists of five subscale scores: symptoms, pain, activities of daily living, sport and recreation function, and knee-based quality of life. The KOOS subset consisted of 67 subjects (33 OMS103HP and 34 vehicle).

“We are pleased with the clinical results of this Phase 2 trial, which show that OMS103HP significantly improved patients’ functional scores, increased their knee flexion and decreased their pain after arthroscopy,” stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros.  “These data are not only consistent with those from our earlier Phase 2 arthroscopic ACL trial that demonstrated functional improvement over a 30-day course of physical therapy, they showed sustained clinical benefit throughout an even longer 90-day follow-up period.”

About OMS103HP

OMS103HP is being developed for use during arthroscopic surgery to reduce postoperative pain and improve postoperative joint motion and function.  OMS103HP is injected into standard arthroscopic irrigation solutions and perfused through the joint in low concentrations during surgery.  It is currently being evaluated in a Phase 3 clinical program for anterior cruciate ligament (ACL) surgery and has also completed a Phase 2 clinical trial for meniscectomy surgery.  If approved, OMS103HP would be the first commercially available drug delivered directly to the surgical site to improve function following arthroscopic surgery.

About Meniscectomy Surgery

Arthroscopic meniscectomy is a minimally invasive surgical procedure to remove or repair a torn meniscus cartilage in the knee. Postoperative recovery to normal function may take months.  Approximately four million arthroscopic operations were performed in the United States in 2006, including 2.6 million knee arthroscopy operations.

About Omeros Corporation

Omeros is a clinical-stage biopharmaceutical company committed to discovering, developing and commercializing products focused on inflammation 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 five ongoing clinical development programs, including four from its PharmacoSurgery™ platform and one from its Addiction program, the most advanced of which is in Phase 3 clinical trials. Omeros may also have the near-term capability, through its GPCR (G-protein coupled receptor) program, to add an unprecedented number of wholly new drug targets to the market. Behind its clinical candidates and GPCR platform, Omeros is building a diverse pipeline of antibody and small-molecule preclinical programs targeting inflammation and central nervous system disorders.

Conference Call and Webcast Today at 4:30 p.m. Eastern Time

The Omeros management team will host a conference call today, March 31, at 4:30 p.m. Eastern Time (1:30 p.m. Pacific Time), to discuss the OMS103HP Phase 2 clinical data, as well as the Company’s fourth quarter and year-end 2009 financial results and development highlights.  Interested parties may participate in the conference call by dialing 888-500-6973 (United States and Canada) or 719-457-2637 (International). In addition, the live conference call is being webcast and can be accessed on the “Events” page of the Company’s website at http://www.omeros.com.

A replay of the webcast will be available on the Company’s website for one week.  A telephone replay will also be available for one week starting at 7:30 p.m. Eastern Time on March 31, which can be accessed by dialing 888-203-1112 (United States and Canada) or 719-457-0820 (International) and entering conference ID number 2664433.

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. 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 19, 2009. 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.