Omeros Announces Toxicology Data that Support Advancing MASP-2 Inhibitor into Clinical Trials

SEATTLE, March 28, 2013 /PRNewswire/ -- Omeros Corporation (NASDAQ: OMER) today announced data from toxicology studies evaluating OMS721, the lead human monoclonal antibody in Omeros' mannan-binding lectin-associated serine protease-2 (MASP-2) program. In non-human primates and rodents, there were no drug-related findings in the toxicology assessments, including gross pathology, histopathology (still ongoing in the rodent), clinical signs and clinical chemistries. Omeros expects to submit a European Clinical Trial Application (CTA) in the second quarter of this year to initiate clinical trials evaluating OMS721.

Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2, a novel pro-inflammatory protein involved in activation of the complement system – an important component of the immune system. The complement system plays a role in the inflammatory response to tissue damage or microbial infection. OMS721 selectively inhibits MASP-2, blocking the lectin pathway of the complement system while leaving intact the classical pathway, or the acquired immune response to infection. The Company has conducted a series of in vivo studies that suggest that MASP-2 inhibition may have a preventive or therapeutic effect in the treatment of atypical hemolytic uremic syndrome (aHUS), HUS, wet age-related macular degeneration (AMD), paroxysmal nocturnal hemoglobinuria (PNH), transplant-related complications, ischemia-reperfusion injury, and other immune-related disorders.

The studies reported today in both primates and rodents provide the primary safety data expected to support the initiation of OMS721 clinical studies in mid-year 2013. The pharmacokinetic results in primates demonstrated that subcutaneous administration of OMS721 resulted in maximal inhibition of the lectin pathway within six hours of administration and maintained it for two or more weeks. In addition, the bioavailability and pharmacokinetics observed in both species are expected to support subcutaneous administration in patients at a frequency of once weekly, bi-monthly or possibly at even longer intervals. The only currently approved complement inhibitor requires an intravenous infusion lasting 30 minutes or longer in the hospital or doctor's office.  Subcutaneous dosing avoids the complexity and inconvenience of intravenous infusion and would allow patients to self-administer OMS721 at home.

"As we wrap up our CTA-enabling studies, OMS721 continues to impress with its potential competitive advantages, including subcutaneous administration, convenient dosing, and maintenance of the acquired immune response to infection," stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. "OMS721 holds significant promise to treat a wide range of immune-related disorders, and today's data further underscore the commercial opportunities for OMS721.  We plan to focus initially on aHUS, a rare and life-threatening indication seen most commonly in children. Submission of our CTA is expected next quarter, and we look forward to evaluating the drug product soon in clinical trials."

About Omeros' MASP-2 Program

Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2, a novel pro-inflammatory protein target involved in activation of the complement system, which is an important component of the immune system. The complement system plays a role in the inflammatory response and becomes activated as a result of tissue damage or microbial infection. MASP-2 appears to be unique to, and required for the function of, one of the principal complement activation pathways, known as the lectin pathway. Importantly, inhibition of MASP-2 does not appear to interfere with the antibody-dependent classical complement activation pathway, which is a critical component of the acquired immune response to infection, and its abnormal function is associated with a wide range of autoimmune disorders. MASP-2 is generated by the liver and is then released into the circulation. Adult humans who are genetically deficient in one of the proteins that activate MASP-2 do not appear to be detrimentally affected by the deficiency. Therefore, Omeros believes that it may be possible to deliver MASP-2 antibodies systemically.

Omeros also believes that it has identified the proteins that activate the complement system's alternative pathway, which is linked to a wide range of immune-related disorders. In addition to its lectin pathway inhibitors, the Company is advancing the development of antibodies that would block activation of the alternative pathway alone or in combination with the lectin pathway.

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, OMS302 for lens replacement surgery and OMS103HP for arthroscopy, 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 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 a CTA for OMS721 and begin clinical trials; that OMS721 may be delivered subcutaneously and the frequency of dosing; the diseases that may be treated by OMS721; the potential competitive advantages of OMS721; 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 Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 18, 2013. 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.

SOURCE Omeros Corporation