In reversal, Sarepta to face FDA’s panel of outside experts on Duchenne gene therapy
Sarepta now will have a public hearing with the FDA’s panel of outside experts on its Duchenne muscular dystrophy gene therapy, it said Thursday afternoon. The announcement comes just two weeks after Sarepta said the FDA told the company it had no plans for an advisory committee meeting.
A date has not been set for the adcomm meeting, but it will be held sometime before the FDA’s deadline of May 29 to decide whether or not to grant the therapy accelerated approval. In an investor call, Sarepta CEO Doug Ingram emphasized that the decision was not related to any new data or analysis.
The meeting, he said, will likely focus on the clinical trial’s surrogate endpoint — expression of dystrophin, an enzyme that protects muscles when they expand and contract that people with Duchenne do not make functional versions of, leading their muscles to atrophy over time. The therapy, known as SRP-9001, delivers a gene that encodes for a shortened version of dystrophin and is meant to be a long-term treatment for the disease.
“I think the fact that this is one of the first times that this accelerated approval pathway and surrogate endpoints are being used for an in vivo gene therapy plays some role in this decision, and then some part of it just relates to the fact that the division does have the right to change its mind on things. And I think that, you know, that happened here,” Ingram said during the call.
When the FDA accepted Sarepta’s application for accelerated approval in November, the company had said that an adcomm was expected.
Sarepta has three other drugs for Duchenne muscular dystrophy that were all granted accelerated approval based on surrogate endpoints. None have been converted to a full approval as their confirmatory trials are still running. The three previous drugs are injectable drugs that target certain mutations of Duchenne.
In an emailed statement, FDA CBER spokesperson Paul Richards said a determination was made late in the review process that input from the agency’s gene therapy advisory committee would be important to obtain.
“We recognize the tremendous interest in Sarepta Therapeutics’ gene therapy to treat individuals with Duchenne Muscular Dystrophy,” said the statement. “We have therefore worked expeditiously to schedule an advisory committee meeting, which will be announced in the Federal Register in the near future, in order to facilitate the evaluation of the safety and effectiveness of the product in a timely manner.”
The flip-flop on whether to hold an adcomm comes as the FDA faces a number of changes. The FDA’s Office of Tissues and Advanced Therapies, or OTAT, has turned into the Office of Therapeutic Products, or OTP, under PDUFA VII. The new office will have more funds to work with and will be expanding its workforce, and outgoing OTAT director Wilson Bryan said that a major reorganization was underway.
According to Ingram, OTAT said there were no plans for an adcomm, but OTP reversed course in the recent meeting.
In addition, FDA’s neuroscience chief Billy Dunn, who had a hand in the approval of the previous Duchenne drugs, left the regulatory agency at the end of February. The first Duchenne treatment, Sarepta’s Exondys 51, was approved by the FDA after an advisory committee voted against it.
Sarepta’s stock $SRPT fell 20% in after hours trading.