BioMarin Shares Slammed After Hemophilia A Gene Therapy Stumbles At FDA

BioMarin Pharmaceutical Inc. BMRN shares were plunging Wednesday after a negative outcome for a binary event.

BioMarin Investors Disappointed By FDA News: The FDA issued a complete response letter to BioMarin's biologic license application for valoctocogene roxaparvovec gene therapy for severe hemophilia A, the company said Wednesday.

Investors had a positive bias going into the event based on Phase 2 and 3 efficacy, a growing safety database and positive commentary from BioMarin, Credit Suisse analyst Martin Auster said in a note issued ahead of the FDA news. 

What The FDA Said: In the CRL, the FDA sought two years of data from BioMarin's ongoing 270-301 Phase 3 study to provide substantial evidence of a durable effect using the annualized bleeding rate as the primary endpoint.

The agency highlighted the differences between Study 270-201 Phase 1/2 and the Phase 3 study that limited its ability to rely on the Phase 1/2 study to support durability of effect, BioMarin said.

The last patient in the Phase 3 study will complete two years of follow up in November 2021, the company said. 

"We are surprised and disappointed that the FDA introduced new expectations for the first time in the Complete Response Letter. We are confident in valoctocogene roxaparvovec gene therapy and its potential to redefine the treatment paradigm for people with hemophilia A," CEO Jean-Jacques Bienaimé said in a statement. 

What's Next For BioMarin? The ongoing valoctocogene roxaparvovec clinical trials will continue even as BioMarin explores next steps to obtain approval, the company said. 

The European Medicines Agency review of the company's marketing authorization application for valoctocogene roxaparvovec is ongoing, BioMarin said. 

Credit Suisse previously predicted a $10-$15-plus downside per share in the event of a manageable delay of less than one year.

BMRN Price Action: BioMarin shares were down 35.9% at $75.98 at last check Wednesday. 

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