Sarepta Therapeutics' stock experienced a significant after-hours plunge of 5.17% following the release of its first-quarter 2026 financial results.

While the company reported a positive swing to net income and beat earnings expectations, investors reacted negatively to a 2% year-over-year decline in quarterly revenue to $730.8 million. The decline was primarily driven by a sharp 73% decrease in sales of its flagship gene therapy, ELEVIDYS, which fell to $101.97 million. Overall product revenues dropped 46% to $330.5 million.

The significant drop in ELEVIDYS demand is attributed to an updated product label that restricts treatment to ambulatory patients, significantly reducing the total addressable market for the therapy. This follows safety events in the previous year and a regulatory crackdown that led to temporary shipment pauses. Despite collaboration revenue growth from milestone payments, including from Roche for the launch of ELEVIDYS in Japan, it was insufficient to offset the weakness in core product sales.