In case you missed it, the FDA ad comm for Sarepta’s SRP-9001 Duchenne muscular dystrophy drug candidate was held on Friday, May 12. Duchenne is a rare genetic disease, mostly affecting boys, that causes muscle degeneration and weakness. For many – including those outside of the Duchenne community – the meeting was much anticipated.
Let’s get into this briefly, discuss the ad comm results and turn to the implications for drug manufacturers more broadly.
This ad comm is the first for a Duchenne therapy since 2016. At that time, the ad comm discussed Sarepta’s other Duchenne therapy, Exondys 51. The committee voiced concerns that the data did not provide clear evidence of efficacy. However, the FDA approved the drug, as the committee’s recommendation is not binding. Many believe that high unmet patient need and strong pleas from the patient advocacy community swayed the FDA (hundreds of patients and family members traveled to the meeting). This was one of the most contentious FDA approvals in recent memory.
This time around, the ad comm is focused on Sarepta’s Duchenne gene therapy candidate, SRP-9001. This is the first time a company has asked the FDA to grant accelerated approval to a gene therapy. Despite briefing documents citing skepticism around efficacy (whether the surrogate marker – 9001 dystrophic – reasonably predicts clinical benefit) the committee narrowly voted 8-6 to recommend its accelerated approval.
So, what likely tipped the scale? Once again, the Duchenne community was vocal and prominent. The community has done an exceptional job of amplifying their voice to ensure regulatory decisions are made with their experiences front of mind.
"There was little chance the vote would have been positive if not for the engagement by patient advocates during the whole development and review process," William Blair analyst Tim Lugo said in a note on Monday, describing the close nature of Friday's voting. – Reuters, May 15, 2023
Implications for manufacturers
Both of Sarepta’s ad comms touch on the power of the patient voice. While this is true, it may leave the impression that a patient advocacy rally at the 11th hour will push a drug through to FDA approval.
The reality is, building a drug’s value story starts much, much earlier. Early in drug development, manufacturers need to engage patients to understand what clinical trial endpoints are meaningful to them (particularly when endpoints are considered more subjective or based on a surrogate biomarker).
On top of this, it’s equally important that broader stakeholders – such as KOLs, regulators, and payers – are aligned with these points well ahead of public meetings like an ad comm. There are a lot of deliberate moments and interactions with external stakeholders that should occur prior.
All of this also dovetails with the FDA commissioner’s desire to place more emphasis on patient and KOL discussion at ad comms vs. emphasizing the vote.
“The most important thing to me about the advisory committees is that the purpose is not to take a vote on the approval of a product,” [The voting is] “a habit, it’s not a requirement, and it’s not very useful. I’d like more advisory committees to be about the thinking about the field and the intervention that’s being assessed, not so much the approval decision”. – FDA Commissioner, Robert Califf (March 2023)
The FDA is slated to make a decision on the accelerated approval of SRP-9001 by May 29. The industry will be watching this decision closely, as well as the company’s subsequent price disclosure.
The FDA decision will also be a defining moment for gene therapies. The FDA’s top official, Peter Marks, put forth a couple months ago that the FDA is moving to encourage the use of disease-related biomarkers that may predict efficacy for gene therapies for diseases with small patient populations rather than waiting for definitive proof of patient benefit. Will the FDA’s decision on May 29th back this up?
Authored by Leigh Ann Bruhn and Madeline Corrigan