The U.S. Food and Drug Administration has found minor deficiencies in Mylan NV's application for a generic version of GlaxoSmithKline PLC's blockbuster asthma treatment Advair Diskus.

Advair Diskus generated £3.13 billion in full-year 2017 global revenues, including £1.61 billion in the U.S.

Canonsburg, Pa.-based Mylan said it expects the regulator to issue a complete response letter identifying the issues on June 27.

The application for the product has received a priority designation, and Mylan believes it could get approval for the treatment before the standard 90-day time period after the date of its response to the FDA's letter.

In February, the FDA rejected Novartis AG's application for a generic version of Advair.