X0306 4 2018-01-03 0 0001285819 OMEROS CORP OMER 0001472163 Kelbon Marcia S. 201 ELLIOTT AVENUE WEST SEATTLE WA 98119 0 1 0 0 VP Patent and General Counsel Common Stock 2018-01-03 4 M 0 62528 9.37 A 239169 D Common Stock 2018-01-03 4 S 0 62528 21.45 D 176641 D Common Stock 2018-01-03 4 M 0 3000 6.05 A 179641 D Common Stock 2018-01-03 4 M 0 5004 6.05 A 184645 D Stock Option (Right to Buy) 9.37 2018-01-03 4 M 0 62528 0.00 D 2023-09-24 Common Stock 62528 40972 D Stock Option (Right to Buy) 6.05 2018-01-03 4 M 0 3000 0.00 D 2020-03-28 Common Stock 3000 0 D Stock Option (Right to Buy) 6.05 2018-01-03 4 M 0 5004 0.00 D 2020-03-28 Common Stock 5004 69996 D Open market sale pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 8, 2017, at which time the trading schedule, including sale periods, price and the number of shares to be sold, was established in accordance with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. The options previously vested and became exercisable in 48 equal monthly installments, with a vesting commencement date of April 1, 2013. On January 3, 2018, the reporting person paid the exercise price and exercised options to purchase 3,000 shares of the company's common stock. These shares have not been sold and are held for the account of the reporting person. The options previously vested and became exercisable in 48 equal monthly installments, with a vesting commencement date of November 1, 2009. On January 3, 2018, the reporting person paid the exercise price and exercised options to purchase 5,004 shares of the company's common stock. These shares have not been sold and are held for the account of the reporting person. The options previously vested and became exercisable in 48 equal monthly installments, with a vesting commencement date of April 1, 2010. /s/ Marcia S. Kelbon 2018-01-05