FDA hits pause on another of PepGen's muscular dystrophy trials

Another of PepGen’s trials has encountered resistance from the FDA, with the regulator now putting the company’s plans to launch a phase 2 trial of its Duchenne muscular dystrophy (DMD) therapy on hold.

The CONNECT2-EDO51 trial is designed to test PepGen’s PGN-EDO51 exon-skipping therapy over 25 weeks in patients with DMD. In a short press release Monday morning, the biotech didn’t offer any rationale for the FDA’s refusal to allow the trial to proceed in the U.S. but pointed out that a U.K. version of the study is already open.

PepGen’s shares dropped 29% in premarket trading Monday to $3.32 from a Friday closing price of $4.68.

“We intend to work closely with the FDA to address their questions on our application to initiate CONNECT2 as expeditiously as possible,” PepGen’s head of R&D Paul Streck, M.D., said in the release.

“Our open-label CONNECT1-EDO51 multiple ascending dose study of PGN-EDO51 in boys and young men living with DMD continues as planned in Canada,” Streck added. “We have completed enrollment of the 10 mg/kg dose cohort; all four patients in this cohort have received at least one dose.”

In a third-quarter earnings release last month, PepGen’s CEO James McArthur, Ph.D., said the “encouraging” results from the 5-mg/kg cohort of the CONNECT1-EDO51 trial helped the company “further optimize” the design of the CONNECT2-EDO51 study.

The company was engaging with European regulators about the trial and had been planning to launch the study in the U.S. before the end of the year, PepGen said at the time.

It’s not the first time the company has encountered a holdup from the FDA. Last year, the regulator placed a phase 1 study of the biotech’s myotonic dystrophy drug on hold for a few months. Few details were released about the nature of the agency’s concerns, but the issue seems to have revolved around dosing of the oligonucleotide therapy.