Two Years After Paying $680M, BioMarin Shelves Duchenne Drug

Xconomy San Francisco — 

BioMarin Pharmaceutical took a $680 million gamble when it bought Prosensa in 2014 for its experimental Duchenne muscular dystrophy treatment. Drisapersen (Kydrisa) had already failed a Phase 3 trial, but BioMarin bet it could dig through the data and win FDA approval.

It lost that bet, and now BioMarin (NASDAQ: BMRN) is pulling the plug on the drug. Drisapersen was rejected by the FDA in January, a few months after an advisory panel skewered the data BioMarin brought to the meeting. The final blow came today, as BioMarin said regulators in Europe were likely to reject the drug, as well.

Specifically, BioMarin said today that discussions with the Committee for Medicinal Products for Human Use—a group European regulators look to for guidance on drug approvals—“clearly indicated” that the committee intended to issue a negative opinion on drisapersen.

As a result, BioMarin will no longer try for drisapersen approval in Europe. It will stop developing drisapersen well as three other follow-on drugs—BMN 044, BMN 045, and BMN 053—currently in mid-stage testing for different forms of Duchenne. BioMarin will try to come up with a “transition plan” for patients currently being treated with drisapersen or the other experimental drugs, and will turn its attention to “next generation” RNA-based treatments for Duchenne. In a statement, BioMarin chairman and CEO Jean-Jacques Bienaimé called the developments a “difficult but necessary decision.”

San Rafael, CA-based BioMarin bought Prosensa of Leiden, Netherlands, for $17.75 a share, or a total of $680 million up front, in November 2014. The deal also included two big $80 million milestone payments tied to regulatory approvals in the U.S. and Europe that Prosensa shareholders will now never see.

BioMarin made the buyout one year after Prosensa and then-partner GlaxoSmithKline announced that drisapersen had failed a Phase 3 trial. With news f the failure, Prosensa lost most of its value, and GSK bailed on the drug shortly thereafter.

Still, Prosensa began assembling an FDA application for drisapersen based on the idea that certain subsets of Duchenne patients with Duchenne showed a meaningful benefit. The progressive, fatal genetic disorder robs boys of their ability to walk and typically kills them by their mid-20s.

BioMarin continued Prosensa’s plan after its acquisition. As Bienaimé said on a conference call at the time: “Our belief is that the totality of the Duchenne data combined with the significant unmet need in this patient population provide support for regulatory approval.”

BioMarin made that argument in front of the FDA’s advisory panel last November, but the FDA didn’t flinch. It rejected drisapersen in January, saying the “standard of substantial evidence of effectiveness has not been met.” All eyes then turned to Europe, where regulators had not yet begun their evaluation. Yet expectations were low; as RBC Capital Markets analyst Michael Yee wrote in a note to investors this afternoon, BioMarin’s decision to pull its approval application in Europe “is no surprise.”

The stakes for Duchenne patients have continued to climb. The FDA rejected a second Duchenne drug, from PTC Therapeutics (NASDAQ: PTCT), in February. The only potential treatment remaining on the near-term horizon is a drug from Cambridge, MA-based Sarepta Therapeutics (NASDAQ: SRPT) called eteplirsen. The FDA delayed a decision on that drug last week without saying when an announcement could come down.

Incidentally, meanwhile, two other large biotech acquisitions have also blown up in the past week. Teva Pharmaceutical said today that the FDA rejected the Huntington’s disease drug it acquired when it bought Auspex Pharmaceuticals for more than $3 billion in March 2015. And last Friday, regulators didn’t approve a kidney disease drug AstraZeneca bought when it paid $2.7 billion for ZS Pharma in November.