With a confirmatory trial for Sarepta Therapeutics’ Duchenne muscular dystrophy trial ending in failure, Pfizer’s chief scientist says the pharma giant’s gene therapy is now “the main game in town.”
When asked about yesterday’s DMD data drop from competitor Sarepta on Pfizer’s third quarter earnings call Oct. 31, CEO Albert Bourla said, “it is very, very bad news for patients,” noting that solutions are very limited for people with the severe genetic disease.
“This makes our gene therapy in a way the main game in town,” CSO and President of R&D Mikael Dolsten, M.D., Ph.D., said on the call.
Sarepta shared yesterday that its approved DMD gene therapy Elevidys failed to hit the primary goal of a pivotal study. The endpoint, a measure of motor function called the North Star Ambulatory Assessment, failed to reach statistical significance in the phase 3 study. Following the data reveal, the company’s share price tumbled about 41% to $63.19 midday Tuesday.
When asked about progress on Pfizer’s own DMD program, a gene therapy currently being tested out in a phase 3 trial, Dolsten said there is an opportunity for an interim analysis by the end of this year, though he did not specify whether Pfizer would be taking that opportunity or not. The final analysis is expected by the second half of 2024, and Dolsten said he’s excited to “let the data tell the story.”
Dolsten said the candidate, known as PF-06939926 or fordadistrogene movaparvovec, has “shown a very consistent effect across biomarkers and functional endpoints.”
The data has also shown “encouraging signals in both the younger and the slightly older boys,” according to Dolsten, who added that those signals weren’t something seen in Sarepta’s data. Both Pfizer’s and Sarepta’s phase 3 studies have enrolled boys ages 4 to 7 years, with Sarepta’s Elevidys receiving accelerated approval in June to treat ambulatory patients ages 4 to 5 years.
Despite the new disappointing data, Sarepta still plans to file for a label expansion to treat “all DMD patients” and convert the accelerated approval into a traditional nod.
Two things could speed up Pfizer’s race to a potential FDA finish: fordadistrogene movaparvovec has nabbed both FDA fast-track and orphan designation. However, the therapy has had to face its own challenges, too.
In December 2021, the FDA placed a clinical hold on Pfizer’s phase 3 study after a patient death was reported in a phase 1 trial evaluating the asset. However, the program was freed from the hold the following spring after Pfizer implemented a protocol amendment and addressed the FDA’s requests regarding a potency assay.