144 0002005787 XXXXXXXX LIVE 0001285819 OMEROS CORPORATION 001-34475 201 Elliott Avenue West SEATTLE WA 98119 2066765000 DAVID BORGES Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

10906 203178.78 72388316 08/21/2026 NASDAQ Common 08/21/2026 Exercise of Stock Options Issuer N 10906 08/21/2026 Cash N 10b5-1 Sales for DAVID JOSEPH BORGES

201 Elliott Avenue West SEATTLE WA 98119

Common 08/13/2026 5000 84750.00 The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale. 08/21/2026 02/10/2026 /s/ David Joseph Borges