The FDA has broadened the label for Sarepta Therapeutics’ gene therapy for Duchenne muscular dystrophy to patients ages 4 and older.
The approval goes beyond the patient population in which the company reported data for its randomized clinical trials. It includes a full approval for Duchenne patients who are not dependent on a wheelchair, and an accelerated approval for those who are wheelchair-dependent.
Marketed as Elevidys, the gene therapy was initially given accelerated approval last year for boys ages 4 and 5 who have Duchenne muscular dystrophy. It’s meant to slow progression of the aggressive muscle disease, and the expansion to older boys has long been awaited by families of patients who have few treatment options. The therapy costs $3.2 million in the US.
There have been signs the FDA was going to expand the therapy’s label. Earlier this year, CBER Director Peter Marks made comments suggesting he was open to doing so. And when Elevidys was initially approved, Marks overruled FDA reviewers who had recommended to reject it.
Marks again overruled FDA staff in broadening the label of Sarepta’s gene therapy. Memos that were released Thursday with the agency’s decision showed that two top FDA officials, Lola Fashoyin-Aje and Nicole Verdun, recommended rejecting the gene therapy in favor of an additional confirmatory study but were overruled by Marks.
It’s been debated whether the evidence has been strong enough to back the expansion. In October, the company reported that the Phase 3 EMBARK study failed to meet its primary endpoint. Intended as a confirmatory study, it showed that boys ages 4 to 7 who got Elevidys didn’t do better on a 17-item motor skill test than those who got placebo.
However, the study met key secondary endpoints — measuring boys’ ability to stand and walk — that Sarepta cited when asking the FDA to approve the therapy for boys with Duchenne regardless of their wheelchair status or age. Continued approval for non-ambulatory Duchenne patients may depend on results from a confirmatory trial, which Sarepta said would be the Phase 3 ENVISION study with non-ambulatory and older ambulatory people with Duchenne.
In its first six months on the market, Elevidys generated $200 million in revenue, reflecting strong demand for the therapy. The company’s stock $SRPT was up 35% in after-hours trading.
It’s also been helped by the failure of a potential competitor: Last week, Pfizer announced that its Duchenne gene therapy did not succeed in a Phase 3 study. Pfizer’s therapy did not meet any of the secondary endpoints that Sarepta pointed to when asking for its label expansion.
Editor’s note: This story was corrected to reflect that Elevidys is approved in the United Arab Emirates, Qatar, Kuwait, Bahrain and Oman. A previous version said that it was not approved anywhere else in the world.