By Mackenzie Tatananni
Sarepta Therapeutics stock has gotten hammered over the past year amid fallout from its controversial treatment for Duchenne muscular dystrophy. But shares rallied Wednesday as investors turned their attention to two other drug candidates.
Sarepta reported its first clinical results from two programs for different types of muscular dystrophy. The investigational therapies at the center of the trials, tentatively named SRP-1001 and SRP-1003, belong to a class of small interfering RNA treatments that "silence" specific genes by reducing protein production.
A single dose of the drugs -- SRP-1001 in patients with facioscapulohumeral muscular dystrophy type 1, and SRP-1003 in patients with myotonic dystrophy type 1 -- "support reduction, or knockdown, of the target protein or mRNA," Sarepta said. "In both studies, the majority of adverse events were mild to moderate and were not dose dependent."
Sounds compelling enough. The stock spiked 29% to $22.67 on Wednesday, on pace for the largest single-day percent increase since June 2024, according to Dow Jones Market Data. The benchmark S&P 500 ticked up 0.6%.
But investors may have been getting ahead of themselves. A second look reveals the data were "thin and somewhat mixed," according to Leerink Partners analyst Joseph Schwartz.
"On one hand, it seems like they can achieve impressive muscle concentration, and the DUX-4 reduction looks good," Schwartz said, referring to a reduction in a protein that causes FSHD when mis-expressed.
At the same time, the data for myotonic dystrophy type 1 were limited, "while safety remains an open debate," Schwartz continued. He pointed out that the stakes were higher than usual, seeing as the company had pushed its data readout from the second half of 2025 to early 2026.
"After the wait, we think investors may be disappointed by the breadth of data disclosed," Schwartz said. He noted that the results only included single ascending dose results across a limited number of cohorts while omitting other "key measures."
Still, the stock move is unsurprising given the low bar Sarepta had to clear. The stock has gotten pummeled over the past 12 months following the deaths of three patients receiving Sarepta's gene therapies. Even including Wednesday's gains, shares remain down nearly 70% over that period.
Two deaths, including that of an eight-year-old, occurred in patients treated with Elevidys, while the third occurred in a patient taking one of Sarepta's investigational treatments for limb-girdle muscular dystrophy.
The first two patients were living with Duchenne muscular dystrophy, a debilitating condition that causes muscles in the body to break down over time, primarily in young boys. Given that most patients with Duchenne muscular dystrophy only survive into early adulthood, Sarepta was already working within a vulnerable population, something management has flagged on calls with investors.
Still, the string of deaths alarmed Wall Street and the medical community alike. Sarepta temporarily paused Elevidys shipments for non-ambulatory patients in June 2025 as management met with regulators and consulted an expert committee.
One month later, following the death of a third patient, the Food and Drug Administration informally requested that Sarepta halt all shipments of Elevidys. The company initially refused, insisting that the drug remained safe for ambulatory patients.
But pressure was mounting. The same month, one of the largest Elevidys treatment centers at Children's Hospital Los Angeles decided to halt infusions due to safety concerns.
Sarepta ultimately reversed course and announced a voluntary pause on all U.S. shipments, with CEO Doug Ingram attributing the decision to a need to maintain a "productive and positive working relationship" with regulators.
While the pause is over, it has changed the way Elevidys is sold. The treatment is now indicated only for ambulatory patients aged 4 and older. The package carries a boxed warning -- the FDA's most serious safety signal -- highlighting the risk of fatal liver injury.
To Sarepta's credit, the company shared safety details for both of its latest trials on Wednesday, Schwartz said. Management noted that SRP-1003 has a "reassuring safety profile" with no serious, unexpected negative outcomes during the course of treatment.
Still, investors may be spooked by an unrelated abnormal heart rhythm that occurred in one patient following treatment, which was ultimately fatal. While patients with myotonic dystrophy type 1 often experience cardiac abnormalities, "this is still something to watch," Schwartz said.
Write to Mackenzie Tatananni at mackenzie.tatananni@barrons.com
This content was created by Barron's, which is operated by Dow Jones & Co. Barron's is published independently from Dow Jones Newswires and The Wall Street Journal.
(END) Dow Jones Newswires
March 25, 2026 12:17 ET (16:17 GMT)
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