Core Viewpoint - The U.S. FDA has placed a partial clinical hold on PepGen's midstage trial for its muscle disease drug PGNEDODM1, leading to a significant drop in the company's shares by over 25% in extended trading [1]. Company Summary - PepGen is developing PGNEDODM1 for myotonic dystrophy type 1, a genetic condition that causes muscle weakness and tightening over time [1]. - The FDA's concerns are based on earlier laboratory and animal studies submitted by PepGen, but no safety issues were raised from patient data in an early-stage study [1]. - PepGen is collaborating with the FDA to address the concerns and plans to submit additional information, including new data from the earlier study [1]. - While the U.S. trial is on hold, PepGen has received approval to initiate the study in South Korea, Australia, and New Zealand [1]. - Patients in the UK and Canada are currently being treated at a 10 mg/kg dose, following a recommendation from an independent safety board for dose escalation [1]. - As of December 31, 2025, PepGen reported having $148.5 million in cash and investments, sufficient to fund operations into the second half of 2027 [1].