A biotechnology company saw its stock value plummet more than 25% in after-hours trading Wednesday following news that federal health officials have temporarily suspended its clinical trial for a rare muscle disorder treatment.
The Food and Drug Administration imposed a partial clinical hold on PepGen’s mid-stage testing of PGN-EDODM1, an experimental therapy designed to treat myotonic dystrophy type 1. This inherited condition gradually weakens muscles and causes them to contract involuntarily, creating difficulties with movement and everyday tasks.
According to PepGen, the FDA’s decision stems from questions about laboratory and animal research data the company had previously provided to regulators.
However, the agency has not identified any safety issues related to patient information collected during earlier human testing phases.
Company officials stated they are collaborating with the FDA to resolve the regulatory concerns and plan to provide additional data, including recently revealed results from prior studies.
Despite the American suspension, PepGen has received authorization to launch the trial in South Korea, Australia, and New Zealand.
The study is already underway in the United Kingdom and Canada, where patients are receiving the 10 mg/kg dosage after an independent safety monitoring committee recommended proceeding with higher dose levels.
The clinical hold affected no American participants since patient enrollment had not yet begun in the United States.
PepGen reported having $148.5 million in cash and investments at the end of December 2025, providing sufficient funding for company operations through mid-2027.
