X0303 4 2011-05-27 0 0001285819 OMEROS CORP OMER 0001472161 Demopulos Peter A MD 1420 FIFTH AVENUE SUITE 2600 SEATTLE WA 98101-2347 1 0 0 0 Stock Option (Right to Buy) 4.53 2011-05-27 4 A 0 5000 0 A 2021-05-26 Common Stock 5000 5000 D This Option shall fully vest and become exercisable on the date that is immediately prior to the day of the next annual meeting of the shareholders of the Company held after the Date of Grant of this Option, provided that the Participant continues to serve as a director of the Company through such date. /s/ Alex F. Sutter, attorney-in-fact on behalf of Peter A. Demopulos, M.D. 2011-05-31