Sarepta must also run a post-marketing study for Elevidys to better assess the risk of serious liver injury in patients dosed with the gene therapy.
The FDA on Friday adjusted the label for Sarepta Therapeutics’ gene therapy Elevidys for Duchenne muscular dystrophy, adding a boxed warning to the product to alert patients and prescribers to its risk of serious liver toxicities and risk of death.
The black box warning—the FDA’s most serious safety signal on pharmaceutical products—describes the potential of developing severe liver injury and acute liver failure in patients taking Elevidys, with the risk of these leading to death. The regulator also narrowed the use of Elevidys to ambulatory Duchene patients aged 4 years and up with a confirmed mutation in the DMD gene.
Following these labelling changes, Elevidys can no longer be used in nonambulatory patients.
Reacting to the news, analysts at Jefferies said in a Sunday note that there were “no surprises” with these changes. In fact, they argued, these could even be seen as a positive for Sarepta. “The label update should reassure the Street Elevidys will not be pulled from the market, as long as no add’l deaths occur.”
The removal of the nonambulatory population should also be manageable for Elevidys’ market profile, Jefferies said, especially since shipments of the drug for these patients have been “paused anyway.”
Aside from the safety updates, the FDA also required Sarepta to run a post-marketing observational study with around 200 patients subjected to “periodic” liver function tests for at least 12 months after Elevidys treatment. The goal, according to the regulator, is to “further assess the risk of serious liver injury” of the gene therapy.
Sarepta reported earlier this year that two patients treated with Elevidys died—the first case happened in March followed by a second in June. Both occurred in nonambulatory patients and were linked to acute liver injury leading to liver failure. In July, the biotech announced that it proposed to the FDA to add a boxed warning to Elevidys, as well as a prophylactic immunosuppression regimen for patients dosed with the gene therapy.
Days later, Sarepta logged a third patient death, this time not linked to Elevidys but instead to an investigational gene therapy that used the same adeno-associated virus vector as Elevidys. That candidate was being tested for limb-girdle muscular dystrophy.
Sarepta has since pivoted away from gene therapies to focus on its siRNA pipeline.
