Regenxbio Advances Duchenne Muscular Dystrophy Gene Therapy to Pivotal Studies, Potentially Challenging Sarepta’s Dominance

Regenxbio's RGX-202 Advances to Pivotal Studies:

Regenxbio has aligned with the FDA on an accelerated approval pathway for its investigational gene therapy RGX-202, aiming for a Biologics License Application (BLA) filing in 202625.
The pivotal study will enroll approximately 30 ambulatory patients aged 1 year and older, focusing on significant microdystrophin expression and improvements in functional tests25.

Early Data Shows Promise:

Early data from the Phase I/II AFINITY DUCHENNE trial demonstrated significant functional improvements in all five participants, outperforming natural history controls on both the North Star Ambulatory Assessment (NSAA) and timed function tests24.

Safety Profile:

RGX-202 exhibited a favorable safety profile, with no serious adverse events or adverse events of special interest reported across both dose levels25.

Potential Threat to Sarepta's Elevidys:

Regenxbio's RGX-202 could potentially challenge Sarepta's Elevidys, the only approved gene therapy for DMD, which has shown robust sales but mixed efficacy data15.

Market Dynamics:

Analysts note that while Regenxbio's data is promising, it comes from a small number of patients, and richer datasets are needed before drawing conclusions about its market impact5.

Regulatory Context:

The FDA has released draft guidance to streamline the development and submission of cell and gene therapies, which could support Regenxbio's regulatory path2.

Legal Background:

Regenxbio previously lost a legal battle over a muscular dystrophy treatment patent to Sarepta, which has implications for the broader landscape of gene therapy innovation and patent protection3.

Sources:

1. https://www.biospace.com/business/sarepta-halts-development-of-next-gen-dmd-drug-reports-robust-elevidys-sales

2. https://www.pharmaceutical-technology.com/news/regenxbio-eyes-2026-filing-for-duchenne-muscular-dystrophy-gene-therapy/

3. https://biobuzz.io/regenxbio-and-upenn-lose-legal-battle-over-muscular-dystrophy-treatment-patent-to-sarepta/

4. https://www.biopharmadive.com/news/regenxbio-duchenne-gene-therapy-study-results/709426/

5. https://www.biospace.com/drug-development/regenxbio-gears-up-to-challenge-sarepta-in-dmd-as-gene-therapy-advances-to-pivotal-studies