Rigel's bleeding disorder drug clears first of two key trials

(Reuters) - Rigel Pharmaceuticals Inc said its experimental drug to treat a bleeding disorder met its main goal in the first of two late-stage trials, sending its shares up 12 pct in premarket trade.

The drug, fostamatinib, is being studied to treat chronic immune thrombocytopenia (ITP) in which the immune system attacks and destroys the body’s own blood platelets.

About 18 percent of the 76 adult patients who were treated with fostamatinib achieved a stable platelet response in the study, compared with none on placebo.

Patients typically had an increase in platelet counts to a level above 50,000/uL within the initial weeks of treatment.

ITP patients can suffer extreme bruising, bleeding and fatigue due to low platelet counts. Chronic ITP affects an estimated 60,000 to 125,000 people in the United States.

Rigel said results from the second late-stage trial are expected in October or November.

The company expects to file an application for marketing approval with the U.S. Food and Drug Administration in the first quarter of 2017.

Rigel’s shares had closed at $2.64 on Monday on the Nasdaq.

Reporting by Shailesh Kuber; Editing by Savio D’Souza and Anil D’Silva