Spurned in Duchenne, BioMarin Will Seek Approval For Batten Drug

Xconomy San Francisco — 

BioMarin Pharmaceutical, a developer of treatments for rare diseases, struck out in a recent attempt to have a drug approved for Duchenne muscular dystrophy. Now it’s taking another swing with a drug for a different genetic disease, one that strikes children a couple years after birth, debilitates their bodies and minds, and proves deadly by the time they are teenagers.

BioMarin (NASDAQ: BMRN), of San Rafael, CA, said Wednesday evening that data from a Phase 1/2 study of cerliponase alfa in two dozen patients with CLN2 disease, a form of the genetically inherited Batten disease, were good enough for the company to ask regulators in the U.S. and Europe for marketing approval. The company said it would submit applications by the middle of this year.

In 23 children treated for 48 weeks, 15 had their disease stabilized, which is notable for a disease often marked by rapid degeneration. Children with Batten suffer from seizures, blindness, dementia, and more, and the CLN2 form progresses quickly, with death occurring between the ages of 8 and 12, according to the National Institutes of Health.

The rate of decline in patients’ motor and language function was about 80 percent below the expected rate in untreated patients based on an outside study, not from direct comparison within the same trial.

Seven of the patients had a total of 10 serious side effects related to the drug, and one patient came down with an infection that was cleared up. (The drug is administered through a stent into the brain.) Overall, BioMarin described the treatment as “well tolerated.” One patient left the study, not from side effects but because after one dose her parents chose to withdraw her, according to BioMarin spokeswoman Debra Charlesworth.

Both the tiny size and the design of the study would often not move regulators to give a drug meant for a very prevalent disease with therapies available a green light. But the lack of treatments for the CLN2 form of Batten, its rapid, devastating progression, and the tiny population from which to draw trial volunteers are factors that the company hope will sway the U.S. and European drug agencies.

“Whether FDA will approve this is not clear but stabilization [of disease] is a major treatment effect in these very sick children,” wrote RBC Capital Markets analyst Michael Yee in a research note. If the agencies accept BioMarin’s application, they could make a marketing decision by early 2017.

The positive data come on the heels of a setback for the company. The FDA rejected its drug drisapersen in January, intended for a subset of patients with Duchenne muscular dystrophy.

It was not a surprise. At a meeting in November, FDA advisors had harsh words for drisapersen and BioMarin. Their criticism echoed FDA scientists whose report leading up to the committee meeting called BioMarin’s evidence “inconsistent and in some cases contradictory.”

In pressing for drisapersen’s approval, BioMarin had taken one of the higher profile gambles in recent biotech history. It had bought the drug in 2014 through its $680 million acquisition of Prosensa, which had already conducted a Phase 3 trial that failed. (BioMarin would have paid even more if regulators had approved the drug.)

At the time, BioMarin contended that the Prosensa study was flawed for a variety of reasons, and that a post-hoc analysis pooling data from a number of subgroups showed that drisapersen would in fact benefit Duchenne patients. It had Duchenne patients and their advocates on its side, but their testimony—which made for a dramatic hearing in November—did not sway the FDA.

The CLN2/Batten data has bumped BioMarin stock up nearly 2 percent in after-hours trading as of this writing. The company released interim data from the study in January.

Ben Fidler contributed to this report.