Biomarker data for Sarepta Therapeutics’ RNA programs, licensed from Arrowhead Pharmaceuticals, are “competitive” and “strong,” according to analysts at Jefferies, which projected over $1 billion in peak sales.
Sarepta Therapeutics has unveiled early biomarker data for two of the RNA interference assets it licensed from Arrowhead Pharmaceuticals, plotting a path forward after pivoting away from the gene therapies linked to multiple patient deaths and Sarepta’s cratering valuation.
The embattled biotech’s stock jumped more than 30% to $23.77 following the readout Wednesday, though that’s still a far cry from when shares sat comfortably over $100 before the first Elevidys-linked death was reported in March 2025. Elevidys is Sarepta’s approved gene therapy for Duchenne muscular dystrophy.
This week’s positive news aligns with Sarepta’s plan, announced in last July after two more deaths were linked to its AAV delivery technology, to move away from gene therapies. The biotech got both RNA assets from its December 2024 deal with Arrowhead Pharmaceuticals, which involved a $500 million upfront payment, a $325 million equity investment and up to a whopping $10 billion in milestones.
The first of these two assets is called SRP-1001, which Sarepta is testing for facioscapulohumeral muscular dystrophy (FSHD), a rare genetic disorder that involves progressive weakening of muscles in the face, shoulders and limbs.
A single dose of SRP-1001 resulted in a 90% to 93% reduction in the expression of genes that are abnormally activated in FSHD, according to a company presentation on Wednesday. SRP-1001 likewise rapidly reduced serum creatine kinase levels, a key marker of muscle damage.
These findings are “competitive,” analysts at Jefferies wrote in an investor note on Wednesday, noting that aside from a potentially better efficacy profile, Sarepta’s asset stands out among FSHD candidates because of its longer dosing interval of once every three months.
Sarepta’s second showcase on Wednesday featured SRP-1003, being studied in myotonic dystrophy type 1 (DM1). At its lowest dose, a single injection of SRP-1003 “significantly outperforms” repeated administrations of an antisense oligonucleotide therapy from Dyne Therapeutics and an siRNA therapeutic from Avidity Biosciences, Sarepta claimed in its presentation.
The company cautioned, however, that no head-to-head clinical studies have yet been conducted, and that “cross-trial comparisons may not be reliable.”
Jefferies called the DM1 data “strong,” noting that “SRP-1003 could show superior efficacy/safety and provide less-frequent dosing.”
The firm estimates around $1 billion in peak sales for each of these programs.
The early findings from Sarepta also reflect positively on Arrowhead, analysts at H.C. Wainwright wrote in their own note Wednesday. “In our view, the early data are compelling and appear to validate the core thesis underpinning the deal.”
