Orphan Drug Application Filed for OMS721 for aHUS

Omeros announced that it has filed an Application for Orphan Drug Designation with the FDA for OMS721, the lead human monoclonal antibody in Omeros' mannan-binding lectin-associated serine protease-2 (MASP-2) program, for use in the treatment of atypical hemolytic uremic syndrome (aHUS). OMS721 selectively inhibits MASP-2, blocking the lectin pathway of the complement system while leaving the classical pathway intact, which represents the acquired immune response to infection.

Based on positive preclinical data in thrombotic microangiopathy (TMA), the first indication planned for OMS721 clinical trials is aHUS, a rare but life-threatening form of TMA. OMS721 is designed to be self-administered by subcutaneous injection.

Soliris (eculizumab; Alexion), which received orphan drug status for aHUS , is the only currently approved therapy for that indication.

For more information call (206) 676-5000 or visit www.omeros.com