Omeros Announces Positive Data For MASP-2 Inhibitor In Experimental Model Of Stroke

Omeros Corporation OMER today announced positive data using a derivative of OMS721 in a well-established animal model of stroke. OMS721 is the company's lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (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. Omeros controls the worldwide rights to MASP-2 inhibition and to all therapeutics targeting MASP-2. The study evaluated the effect of MASP-2 blockade on neurological deficits and the size of brain infarcts 48 hours after induction of an ischemic stroke. Compared to control antibody-treated mice, mice treated with MASP-2 antibody demonstrated significantly reduced neurological deficits 48 hours after an ischemic stroke. In addition, the infarcted area of the brain was significantly smaller in MASP-2 antibody-treated mice. A similar degree of protection was also observed in gene-targeted MASP-2-deficient mice, which showed significantly lesser neurological deficits and infarct sizes compared to wild-type control mice. The study was conducted by the team of Dr. Maria-Grazia de Simoni, director of the Laboratory of Inflammation and Nervous System Diseases at the Mario Negri Research Institute in Milan, in collaboration with Dr. Wilhelm Schwaeble, professor of immunology at the University of Leicester and Royal Society-Wolfson Research Merit Award Holder. "The data from this study clearly identify the lectin pathway as a central contributor to the damage and disability resulting from the ischemic injury of stroke," stated Dr. de Simoni. "Our findings are consistent with human clinical data supporting the importance of the lectin pathway in stroke and underscore the attractiveness of MASP-2 as a potential target for the treatment of stroke patients." Every year, more than 800,000 people in the U.S. suffer a stroke, almost 90 percent of which are ischemic, and approximately one out of six are fatal. A leading cause of serious long-term disability, the cost of stroke in the U.S. is estimated at $37 billion annually [http://www.cdc.gov/stroke/facts.htm]. "These results are exciting and expand our understanding of the lectin pathway's central role in ischemia-reperfusion injury across multiple organs, including the brain, heart and kidney," said Gregory A. Demopulos, chairman and chief executive officer of Omeros Corporation. "The importance of the lectin pathway and of MASP-2, the pathway's critical effector enzyme, in the pathogenesis of a wide range of diseases and disorders continues to grow within the complement research community, and Omeros plans to explore a wide range of clinical indications for OMS721 and our MASP programs." OMS721 is currently being evaluated in a Phase 2 clinical trial in patients with complement-mediated thrombotic microangiopathies (TMAs), including atypical hemolytic uremic syndrome (aHUS), thrombotic thrombocytopenic purpura (TTP), and stem cell transplant-related TMAs. Thrombotic microangiopathies are a family of rare, debilitating and life-threatening disorders characterized by multiple thrombi (clots) in the microcirculation of the body's organs, most commonly the kidney and brain. Omeros expects to be able to release data later this month on the effect of OMS721 on thrombus formation in a human ex vivo pathophysiologic system of aHUS using serum from aHUS patients both in the acute phase and in remission.