Regenxbio Touts Positive Biomarker Data From Duchenne Muscular Dystrophy Gene Therapy Trial

Regenxbio Inc RGNX revealed on Wednesday new interim data from two additional patients in the Phase 1/2 portion of the AFFINITY DUCHENNE trial of RGX-202, an investigational gene therapy for Duchenne muscular dystrophy.

Results were presented at the 2025 Muscular Dystrophy Association (MDA) Clinical & Scientific Conference.

At dosing, microdystrophin expression was 122.3% higher in a patient age three compared to the control.

In a patient age seven, RGX-202 microdystrophin expression was 31.5% higher than in the control.

In all patients, RGX-202 was appropriately localized to the sarcolemma, demonstrating the differentiated construct with the CT-Domain is appropriately targeting the muscle.

RGX-202 microdystrophin expression results in ambulatory patients age eight and above are the highest reported microdystrophin levels across approved or investigational gene therapies.

To support a Biologics License Application (BLA) using the accelerated approval pathway, the primary endpoint in the pivotal phase of AFFINITY DUCHENNE is the proportion of participants whose RGX-202 microdystrophin expression is ≥10% at Week 12.

RGX-202 also demonstrates the highest reported vector genome copies (4.9-55.4) measured by qPCR across approved or investigational gene therapies.

As of Feb. 21, 2025, RGX-202 was well tolerated, with no serious adverse events or AEs of special interest. Common drug-related AEs included nausea, vomiting and fatigue. All were resolved and typically anticipated with gene therapy administration.

Phase 3 portion of the AFFINITY DUCHENNE trial is enrolling ambulatory patients (who can walk) aged one and above, on track for BLA submission in mid-2026.

Last week, Regenxbio reported a fourth-quarter loss of $1.01 per share, beating the consensus of $1.15.

Sales decreased slightly from $22.2 million to $21.21 million, missing the consensus of $23.75 million.

Regenxbio expects its cash, cash equivalents and marketable securities of $244.9 million as of Dec. 31, 2024, and the $110 million upfront payment to be received under the Nippon Shinyaku collaboration to fund its operations into the second half of 2026.

RGNX Price Action: Regenxbio stock is up 5.90% at $8.26 at publication Wednesday.

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