(Reuters) – The U.S. Food and Drug Administration has declined to approve BioMarin Pharmaceutical Inc’s gene therapy for bleeding disorder hemophilia A, citing the need for two-year data on the therapy, the drugmaker said on Wednesday.
BioMarin’s shares slumped 21.3% to $93.25 before the bell.
The company said the agency had raised the request for two-year data from an ongoing late-stage study of the therapy for the first time in its so-called complete response letter.
“We are surprised and disappointed that the FDA introduced new expectations for the first time in the Complete Response Letter,” Chief Executive Officer Jean-Jacques Bienaim said in a statement.
The therapy, called valoctocogene roxaparvovec, is one of several gene therapies under development that have been raised as “one-and-done” potential cures.
The treatment aims to enable patients with hemophilia A to make the blood-clotting protein they otherwise lack.
Hemophilia A patients are at risk for painful or potentially life-threatening bleeding from even modest injuries.
(Reporting by Manas Mishra in Bengaluru; Editing by Maju Samuel)
