Investors Hold Their Breath as BioMarin's DMD Drug Gets Grilled by the FDA Today

November 24, 2015
By Alex Keown, BioSpace.com Breaking News Staff

WASHINGTON –Patients with Duchenne Muscular Dystrophy and biotech investors are waiting with bated breath as a U.S. Food and Drug Administration (FDA) advisory panel meets with representatives from California-based BioMarin to discuss approval of drisapersen, which will be marketed as Kyndrisa if approved.

BioMarin researchers and a number of patients seeking relief will likely field questions for most of the day in hopes the panel will recommend approval of the medication.

Advocates for Duchenne Muscular Dystrophy have been clamoring for an approved treatment to the deadly disease for years. It will certainly be a tough fight for BioMarin, especially after the panel released a critical analysis of the drug last week. In its review, the FDA panel outlined a number of concerns about the efficacy of the drug, saying that in some clinical data, the efficacy data is inconsistent and in other areas the data is contradictory. Members of the review panel said the long-term data presented by California-based BioMarin did not warrant approval at the time. The review panel’s recommendations are not the final arbiter for the fate of drisapersen. The committee will hear hours of testimony from patients diagnosed with Duchenne Muscular Dystrophy and their families.

Not only is the BioMarin review critical for that company, it will also have an impact on Sarepta Therapeutics , which is developing its own treatment for DMD, eteplirsen. Sarepta is scheduled to appear before an FDA panel on Jan. 22. Unlike BioMarin, Sarepta’s drug has shown positive results, although the trial size has been small, which may cause some issues. Eteplirsen is designed to target the underlying cause of DMD by enabling the production of a functional dystrophin protein in patients with mutations amenable to exon 51 skipping. Approximately 13 percent of people with DMD are estimated to have a mutation targeted by eteplirsen/exon 51 skipping.

BioMarin beat Sarepta to the FDA with a New Drug Application filed in April for drisapersen. Sarepta filed its NDA for eteplirsen in June. Both drugs utilize “exon skipping” technology, which allows the damaged cells’ repair mechanisms to fix the specific genetic mutation that affects about 13 percent of individuals with the disease.

Additionally, Pfizer Inc. is developing a myostatin inhibitor, PF-06252616 to treat DMD. The pharmaceutical giant is currently conducting a mid-stage clinical trial with results expected in early 2017. Pfizer’s drug may have a wider reach than the treatments being developed by Sarepta and BioMarin, which will only impact about 15 percent of patients with DMD.

BioMarin’s stock is up this morning after tumbling 5 percent last week following the advisory panel’s review. Stock is currently trading at $97.80 per share, but that could change if the hearing goes badly for the company. Shares for Sarepta jumped 11 percent to $37.05 per share Monday.

The hearing will be streamed on the Web. The Boston Business Journal plans to post live hearing updates on its blog today.

Duchenne muscular dystrophy is an X-linked degenerative neuromuscular disorder causing severe progressive muscle loss and premature death. One of the most common fatal genetic disorders, DMD affects approximately one in every 3,500 boys born worldwide. DMD is associated with specific errors in the gene that codes for dystrophin, a protein that plays a key structural role in muscle fiber function. Progressive muscle weakness in the lower limbs spreads to the arms, neck and other areas. Eventually, increasing difficulty in breathing due to respiratory muscle dysfunction requires ventilation support, and cardiac dysfunction can lead to heart failure. The condition is universally fatal, and death usually occurs before the age of 30.