Feb 16 (Reuters) - Sarepta Therapeutics said on Friday that the U.S. health regulator will make a decision on whether to grant traditional approval of its gene therapy Elevidys for a muscle wasting disorder by June 21.

Shares of the drugmaker surged 12% in premarket trading after it said the Food and Drug Administration (FDA) does not plan to hold a meeting of its outside advisers to review the company's application.

The therapy, Elevidys, was granted accelerated approval in June last year to treat Duchenne muscular dystrophy, an inherited progressive muscle-wasting disorder that almost always affects young boys.

However, in October Elevidys failed the main goal in a late-stage trial, raising questions over a traditional U.S. approval for the therapy.

Sarepta is seeking to convert the accelerated approval to a traditional approval, as well as expand the use of the therapy for ages 4 through 7 years, based on data from its late-stage study. (Reporting by Christy Santhosh and Leroy Leo in Bengaluru; Editing by Shailesh Kuber)