FDA blocks much-anticipated BioMarin hemophilia gene therapy

Investors are driving shares of drug developer BioMarin down by a third after U.S. regulators rejected its potentially game-changing gene therapy for hemophilia A patients

FAIRLESS HILLS, PA —
Investors fled drug developer BioMarin in droves on Wednesday, driving shares down by a third after U.S. regulators rejected the company’s potentially game-changing hemophilia A gene therapy over concerns it might not really be a one-and-done lifetime treatment.

The U.S. Food and Drug Administration’s rejection late Tuesday means the San Rafael, California-based company will have to complete an ongoing late-stage patient study, likely delaying possible approval till late in 2022.

The infused therapy, called Roctavian, could have freed hemophilia A patients from frequent, extremely expensive infusions of a blood-clotting therapy to prevent dangerous internal bleeding. It had been highly anticipated by doctors, patients and investors.

In a statement, BioMarin said the company and the FDA previously agreed on how much patient testing data the agency required to review the therapy, but in its rejection letter the FDA for the first time recommended Biomarin finish the late-stage study and provide two years of follow-up data on the therapy’s safety and efficacy in preventing internal bleeding for all study participants.

The company added that FDA concluded differences between the results of a small, early-stage study and interim data from the late-stage study left unclear how long the therapy’s effect would last.

Roctavian was meant to free patients with severe hemophilia A from 100 to 150 IV infusions of Factor VIII per year to prevent or at least reduce painful, spontaneous bleeding into joints and muscles, which can cause permanent damage to them.

Also known as valoctocogene roxaparvovec or valrox for short, it would have been the first gene therapy approved in the U.S. for any type of hemophilia. That’s a rare, genetic bleeding disorder in which people don’t have enough of a clotting protein called Factor VIII due to a mutation in the gene responsible for producing it, and repeatedly suffer internal bleeding. About 1 in 10,000 people have hemophilia A, and about half have severe disease.

The gene therapy works by using an inactivated virus, created in a lab, to deliver to liver cells a working gene via a one-time IV infusion meant to enable the body to produce FVIII on its own.

Questions about whether it would work for a lifetime or just a few years came amid rumors that Biomarin might set a price tag as high as $3 million per patient. That would top the price for the most expensive therapy ever approved by the FDA, Swiss drugmaker Novartis AG’s gene therapy for spinal muscular atrophy, Zolgensma, which was launched in spring 2019 with a $2.125 million price tag per patient.

SVB Leerink analyst Joseph Schwartz on Wednesday slashed his 12-month price target for BioMarin’s stock from $140 to $113 per share. He called the FDA ruling a “major negative surprise,” but added, “We would not sell the stock here, as disappointing as this is.”

Schwartz noted that after BioMarin disclosed disappointing data from an interim analysis of the ongoing late-stage study, company shares dropped to $63. Schwartz believes BioMarin’s other assets are worth an $88 share price.

In afternoon trading, Biomarin Pharmaceutical Inc. shares plunged $42.54, about 36%, to $76. Trading volume by then was about 17 times the usual number of BioMarin shares traded in a day.

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Follow Linda A. Johnson at https://twitter.com/LindaJ—onPharma

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