X0306 4 2013-12-11 0 0001285819 OMEROS CORP OMER 0001472158 Cable Thomas J. 201 ELLIOTT AVENUE WEST SEATTLE WA 98119 1 0 0 0 Common Stock 2013-12-11 4 S 0 5000 7.08 D 72067 D Open market sale pursuant to a 10b5-1 trading plan adopted by the reporting person on October 15, 2013, at which time the pre-determined trading schedule and the number of shares to be sold at market rates was established, in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The terms of this Rule 10b5-1 plan are generally consistent with those of Mr. Cable's prior plan, adopted in July 2012, under which the last trade occurred on July 3, 2013, resulting in a sale of 5,000 shares. This transaction was executed in multiple trades at prices ranging from $7.01 to $7.20; the price reported above reflects the weighted average sales price. The reporting person hereby undertakes to provide full information regarding the number of shares and prices at which the transactions were effected upon request to the SEC staff, the issuer, or a security holder of the issuer. /s/ Marcia S. Kelbon, attorney-in-fact on behalf of Thomas J. Cable 2013-12-13