BioMarin’s Gene Therapy for Hemophilia A Remains on Track for US Approval

Despite the COVID-19 pandemic, BioMarin Pharmaceutical‘s application to the U.S. Food and Drug Administration (FDA) seeking approval of valoctocogene roxaparvovec, an experimental gene therapy for adults with severe hemophilia A, remains on track.

During a conference call, the company also said that if approved, the therapy will be marketed under the brand name Roctavian. (It was previously branded Valrox.)

BioMarin’s biologics license application to the FDA is under priority review. The agency is expected to announce a final decision by Aug. 21

“This milestone represents a tremendous achievement for BioMarin, but the potential approval of the first gene therapy in any type of hemophilia is an even greater triumph for the hemophilia community. They have been waiting decades for this groundbreaking advancement and we are honored to be on this journey together,” Jean-Jacques Bienaimé, chairman and CEO of BioMarin, said in a press release.

“With an approval decision for valoctocogene roxaparvovec expected later this year, our commercial team prepares eagerly to launch what we believe is the most innovative product yet for people with bleeding disorders,” Bienaimé added.

The company also has submitted a similar request to the European Medicines Agency (EMA) in the form of a marketing authorization application. The European Union agency has been reviewing BioMarin’s application under accelerated assessment since January.

However, the company expects EMA’s review process to revert back to a standard procedure. Along with a delay of at least three months due to the COVID-19 pandemic, BioMarin ultimately anticipates an opinion from the Committee for Medicinal Products for Human Use (CHMP) — a branch of EMA whose recommendations on whether to approve therapies are usually  followed by the agency — no sooner than late this year or early 2021.

On behalf of the EMA, the Health Products Regulatory Authority of Ireland has already conducted a pre-approval inspection of BioMarin’s manufacturing facility. A similar inspection by the FDA is expected by the end of June.

Formerly known as BMN 270, the gene therapy uses harmless adeno-associated virus (AAV) vectors to deliver a functional copy of factor VIII — the blood-clotting protein missing or defective in people with hemophilia A — to patients’ cells.

Both U.S. and EU applications were based on updated data from a Phase 1/2 trial (NCT02576795) and on an early analysis of the ongoing Phase 3 GENEr8-1 study (NCT03370913).

Three-year results from the Phase 1/2 trial showed that a single administration of the gene therapy at a dose of 6e13 vg/kg (vector genomes per kilogram) markedly reduced the number of bleeding episodes and the need for factor VIII infusions in a small group of adults with severe hemophilia A.

Updated four-year findings from patients who received this dose and three-year data from those given the lower 4e13 vg/kg dose are expected soon.

The company has already dosed the 134 patients currently participating in GENEr8-1, and expects to announce one-year data in the first quarter of 2021.