October 14, 2016
By Mark Terry, BioSpace.com Breaking News Staff
Back in early January, the U.S. Food and Drug Administration (FDA) turned down San Rafael, California-based BioMarin Pharmaceutical ’s application for Kyndrisa (drisapersen) to treat Duchenne muscular dystrophy (DMD). After a dramatic regulatory battle, the FDA approved Sarepta Therapeutics ’s eteplirsen for DMD in September.
Now it appears that BioMarin, either inspired by Sarepta’s approval or wildly grasping at straws, is considering trying again. In a statement to Endpoints News, BioMarin wrote, “The decision by the FDA to issue a Complete Response Letter for drisapersen is one that can be appealed. BioMarin is exploring its options. The company has not determined if it will pursue an appeal.”
DMD is a muscle wasting disease caused by mutations in the dystrophin gene. The mutations result in a lack of production of the dystrophin protein. The disease is progressive and typically causes death in early adulthood, with serious complications that include heart or respiratory-related problems. It mostly affects boys, about 1 in every 3,500 to 5,000 male children.
The FDA argued that Kyndrisa didn’t show enough benefit. Of the three clinical trials BioMarin ran, two didn’t meet their primary endpoint, which was getting patients taking the drug to walk further in six minutes. It also had serious adverse side effects, including low platelet levels that could lead to serious bleeding problems, kidney toxicity, and ulceration, scarring and atrophy at the injection sites.
And the approval of Sarepta’s eteplirsen, now with a commercial name of Exondys51, was controversial at best. John Carroll, writing for Endpoints News, says, “The FDA’s approval for Exondys51 is shaping up as one of the most controversial on record. Janet Woodcock’s steadfast support for Sarepta and its drug triggered a war inside the agency, as senior-level officials ridiculed the lack of evidence on efficacy and questioned the safety profile that Sarepta had presented. The FDA commissioner even chided Sarepta for using a clearly dodgy study to back its application, but deferred to Woodcock’s experience in the field in allowing the approval to go through.”
Cory Kasimov, an analyst with JPMorgan, summed up BioMarin’s possible appeal in a note, writing, “Given Sarepta’s recent eteplirsen approval, BioMarin is going back to the drisapersen data and plans to discuss with the FDA the potential for an appeal. The company noted that the Exondys51 label contains only dystrophin data, and they believe that by the FDA’s own analysis (in AdCom briefing docs) drisapersen’s dystrophin data looks stronger.”
This news has been met by some criticism, perhaps even mockery. Adam Feuerstein, writing for The Street, said, “Hmmm. Good luck with that one, J.J. Last I remember, drisapersen produced almost zero dystrophin AND caused side effects so severe one FDA reviewer cautioned the drug could kill patients, if approved. Bienaime [Jean-Jacques Bienaime, chairman and chief executive officer] can’t seem to get over the fact that he made a bad mistake acquiring Prosensa. He chose the wrong DMD drug. Talking up the possibility of resurrecting drisapersen is Bienaime’s way of talking more crap about Sarepta, the smaller competitor which beat him.”
Well, and any chance of getting a piece of a market that’s allowing a drug to have a $300,000 price tag with no competitors.
