Key Takeaways
Regenxbio Inc. (RGNX) reported that its gene therapy for Duchenne muscular dystrophy, RGX-202, achieved 93% microdystrophin expression in a pivotal Phase III trial, setting up a potential challenge to Sarepta Therapeutics’ approved treatment with a therapy designed for improved safety and efficacy.
"RGX-202 is the first gene therapy in development for Duchenne to demonstrate strong, statistically significant correlation between microdystrophin expression and functional improvement, a landmark distinction in the field," said Steve Pakola, M.D., Chief Medical Officer of Regenxbio.
The AFFINITY DUCHENNE trial met its primary endpoint with high statistical significance (p<0.0001), with 93% of the 30 evaluated patients achieving microdystrophin expression above 10%. The therapy was well-tolerated, with two reported serious adverse events—a case of subacute myocarditis and one of asymptomatic liver injury—that were managed and resolved without lasting effects.
The positive data de-risks the program and puts Regenxbio on a path to seek accelerated approval from the FDA, targeting a 2027 launch. Success would position RGX-202 as a direct competitor to Sarepta's Elevidys, which has faced safety concerns, and could allow Regenxbio to capture a significant share of the Duchenne treatment market.
RGX-202 is an adeno-associated virus (AAV) gene therapy designed to deliver a novel microdystrophin protein to muscle cells, addressing the underlying cause of Duchenne. Unlike the microdystrophin in Sarepta's therapy, Regenxbio's construct is the only one to include a C-Terminal domain, which has been shown to be crucial for protecting and preserving muscle function and more closely mimics naturally occurring dystrophin. The company believes this differentiated design, combined with a proactive immune suppression regimen and high-purity manufacturing, contributes to the therapy's favorable safety and efficacy profile.
Alongside the trial data, Regenxbio reported a net loss of $90.1 million for the first quarter of 2026. Revenues fell to $6.4 million from $89.0 million a year prior, primarily due to the expiration of U.S. patents for Zolgensma, a therapy developed using Regenxbio's technology and marketed by Novartis. The company ended the quarter with $150.5 million in cash, which it states is sufficient to fund operations into early 2027. This runway excludes a potential $100 million milestone payment from partner AbbVie for their collaboration on sura-vec, a gene therapy for retinal diseases, expected in the second quarter of 2026.
This article is for informational purposes only and does not constitute investment advice.
