Jefferies analysts said these detailed safety outcomes confirm the gene therapy’s positive risk/benefit profile in ambulatory patients with Duchenne muscular dystrophy.
Sarepta Therapeutics presented new safety data for its gene therapy Elevidys, stating that there have been no deaths in ambulatory patients with Duchenne muscular dystrophy treated with the drug.
The Massachusetts biotech showed the Elevidys data at a virtual event hosted Sunday by the Center for Duchenne Muscular Dystrophy at UCLA, according to reporting from Endpoints News on Tuesday.
Writing to investors on Tuesday, Jefferies analysts noted that of more than 1,000 patients treated, there continue to be zero deaths attributed to acute liver failure—the cause of three deaths in non-ambulatory patients treated with Elevidys—in ambulatory patients. Across the global clinical development of Elevidys and its post-marketing studies in the U.S. and beyond, acute liver injuries were documented in 23% of patients.
These data, according to Jefferies, highlight the current positive benefit/risk profile of Elevidys in ambulatory DMD patients, “reconfirming a 0% death rate” in this patient subsegment. Still, the analysts acknowledge that “the Street/community will have low tolerance if an ambulatory DMD death occurred.”
Jefferies also noted that liver toxicities appeared to be “balanced” in clinical and real-world settings, the only exception being in non-ambulatory patients the U.S. In this patient population, serious acute liver injuries were more common in the real-world setting, “suggesting safety may be better managed in clinical settings,” the analysts wrote.
Sarepta also shared data on adverse events that weren’t linked to Elevidys, including six patient deaths unrelated to receiving the gene therapy.
Sarepta reported the first patient death linked to Elevidys in March, with the fatality arising in a non-ambulatory boy who developed acute liver failure after receiving the gene therapy. At the time, Sarepta pointed out that liver injury is a known side effect of gene therapies delivered using AAV vectors, like Elevidys. The company reported a second mortality in June—again in a non-ambulatory patient—pushing it to put in place a host of safety initiatives, including giving the product a black box warning.
Sarepta reported a third patient death last month, though this one was not linked to Elevidys, but to an investigational gene therapy for limb-girdle muscular dystrophy that also used an AAV vector. With three mortalities in quick succession, the FDA asked Sarepta to suspend all U.S. shipments of Elevidys—including to ambulatory patients—a request the company eventually agreed to.
Things seem to be starting to calm down for Sarepta, though. Late last month, the FDA recommended that the hold on ambulatory deliveries be lifted.
