PepGen’s early Phase 2 data lift shares as Ionis and ImmunityBio fall

PepGen reported positive Phase 2 results for PGN-EDODM1, its investigational oligonucleotide for myotonic dystrophy type 1 (DM1). After four monthly doses, the six treated participants in the 10 mg/kg cohort showed average muscle RNA-splicing correction of 46.5%; four had correction above 50%.

The small cohort also showed improvements on measures including hand-opening time, grip strength and mobility. The company reported no serious or severe adverse events or treatment discontinuations at this dose. These early findings need confirmation in larger, longer studies.

PepGen shares rose sharply on the news. Its higher-dose 12.5 mg/kg cohort is fully enrolled, with results expected in the first half of 2027. The study remains subject to a U.S. FDA partial clinical hold following nonclinical findings in mice.

Ionis shares fell after the company cut its sales outlook for Tryngolza, while ImmunityBio shares sagged after quarterly revenue missed estimates despite reporting positive bladder-cancer trial news.