June 6 (Reuters) - Alexion Pharmaceuticals Inc said its drug Soliris, already approved in the United States for the treatment of two rare blood disorders, missed its primary goal in a late-stage trial, sending its shares down 9 percent in extended trade.
The drug is being studied as a potential treatment for refractory generalized myasthenia gravis, a debilitating neuromuscular disease.
Soliris is already approved for the rare blood disorders paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.
Shares of Alexion closed $154.99 on Monday on Nasdaq. (Reporting by Shailesh Kuber; Editing by Shounak Dasgupta)