The FDA placed a partial clinical hold on PepGen’s Freedom2‑DM1 Phase 2 trial after reviewers flagged preclinical pharmacology and toxicology findings — notably blood-pressure drops in mice — despite the absence of similar signals in human Phase 1 data. PepGen said it is cooperating with the agency, provided additional analyses including unblinded Phase 1 data, and is continuing the Freedom2 trial at non‑U.S. sites. PepGen’s shares fell about 19–20% on the announcement. Analysts called the action surprising given the mouse data had been previously submitted; they view the hold as likely resolvable but stress the delay highlights the FDA’s cautious posture on novel oligonucleotide delivery platforms and the regulatory sensitivity around neuromuscular targets.