Omeros Corp (OMER.O) said a late-stage trial of its experimental drug for patients undergoing knee surgery did not meet its main goal, sending the company's shares down as much as 10 percent in extended trade.
The company said the drug -- codenamed OMS103HP -- did not meet a patient-reported measure that comprised questions about knee swelling and stiffness.
A second late-stage trial on the drug remains on track and will begin in the first half of 2013, said the company that focuses on treating inflammation and disorders of the central nervous system.
Omeros's shares were down 6 percent at $5.50 after the bell on Thursday. (Reporting by Prateek Kumar; Editing by Sreejiraj Eluvangal)