Biotechnology company BioMarin Pharmaceutical Inc (Nasdaq:BMRN) said on Thursday that it has submitted its Biologics License Application (BLA) to the US Food and Drug Administration (FDA) for its investigational AAV5 gene therapy, valoctocogene roxaparvovec, for adults with haemophilia A.

The FDA has accepted the BLA under its priority review and breakthrough therapy designation. This is the first marketing application accepted for a gene therapy product for any type of haemophilia in the United States.

Currently, no advisory committee meeting is planned to review the application, The Prescription Drug User Fee Act (PDUFA) action date is 21 August 2020.

The BLA is based on the company's Phase 3 interim analysis of study participants treated with investigational product manufactured by the to-be-commercialized process and three-year Phase 1/2 data. The gene therapy manufacturing facility is located in Novato, California and the facility is ready for inspection to support approval.

In addition, the FDA has accepted the company's Premarket Approval (PMA) application for an AAV5 total antibody assay intended as a companion diagnostic test for valoctocogene roxaparvovec. Approximately 80% of people with haemophilia A in the US do not have pre-existing immunity to AAV5 that would make them ineligible for AAV5-mediated gene therapy treatment.

People living with haemophilia A lack enough functioning Factor VIII protein to help their blood clot and are at risk of painful and/or potentially life-threatening bleeds from even modest injuries.