Omeros Announces Positive Data after Completion of Dosing in Phase 1 Clinical Trial with OMS721

SEATTLE, Feb. 3, 2014 /PRNewswire/ -- Omeros Corporation (NASDAQ: OMER) today announced positive data following completion of dosing in a Phase 1 clinical trial of OMS721, the company's lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2), the key regulator of the lectin pathway of the immune system. OMS721, administered either by subcutaneous injection or intravenous infusion, was well tolerated and achieved the objective of a high degree of sustained lectin pathway inhibition. Omeros expects to initiate a Phase 2 clinical program to evaluate OMS721 in the treatment of thrombotic microangiopathies (TMAs), a family of orphan disorders, including atypical hemolytic uremic syndrome, that occurs in the microcirculation of the body's organs, most commonly the kidney and brain, later this quarter.

This Phase 1 trial is a placebo-controlled, double-blind, single-ascending-dose study to evaluate the safety, tolerability, pharmacodynamics and pharmacokinetics of OMS721 in healthy subjects. Seven cohorts of subjects received OMS721 or placebo by either subcutaneous injection or intravenous infusion at increasing dose levels. Consistent with the previously reported interim Phase 1 clinical data, OMS721 administration was well tolerated in all subjects, there were no drug-related adverse events, and no clinically significant abnormalities on laboratory tests or electrocardiograms have been observed. At the highest dose evaluated, both subcutaneous and intravenous routes of administration resulted in a high degree of inhibition of lectin pathway and successfully achieved the pharmacologic target of sustained inhibition for at least one week. The positive results in the Phase 1 trial enable selection of the dose levels to be evaluated in the Phase 2 program, which will assess the safety and efficacy of OMS721 in patients with disorders thought to involve lectin pathway activation, including TMAs.

Omeros previously reported positive data using OMS721 both in a well-established model of TMA and in a well-established model of age-related macular degeneration (AMD). Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2. MASP-2 is critical to the function of the lectin pathway, one of the principal components of the complement system, a key part of the immune response.

"We are pleased with the results from the final three dosing cohorts in the trial," stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. "Together with our previously reported interim data, we now have a good understanding of the pharmacodynamics and pharmacokinetics of our molecule, and we achieved the targeted duration and level of lectin pathway inhibition, both with intravenous and subcutaneous administration. Subcutaneous administration could prove a significant advantage over the one complement inhibitor on the market and others in development, and we look forward to initiating our Phase 2 clinical trial in TMAs later this quarter."

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 and OMS721, its lead MASP-2 antibody, is designed to be self-administered by subcutaneous injection.

Omeros also believes that it has identified the proteins that activate the complement system's alternative pathway in humans, 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 small-molecule and protein therapeutics targeting inflammation, coagulopathies and disorders of the central nervous system. Derived from its proprietary PharmacoSurgery^® platform, the Company's lead drug product, OMS302 for lens replacement surgery, is currently under review for marketing approval by both the US Food and Drug Administration and the European Medicines Agency with commercial launch planned for 2014. Omeros' five other clinical programs are focused on schizophrenia, Huntington's disease and cognitive impairment; addictive and compulsive disorders; complement-related diseases; and 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 Omeros' unproven preclinical and clinical development activities, regulatory oversight, product commercialization, intellectual property claims, 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 November 7, 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, even if new information becomes available in the future.

SOURCE Omeros Corporation