FDA puts clinical hold on PepGen’s DM1 early-stage trial

Published: May 31, 2023

By Kate Goodwin

BioSpace

The FDA has placed a clinical hold on PepGen‘s Phase I trial of its neuromuscular candidate, which had been planned for the first half of the year. The Boston biopharma’s stock dropped around 18% post-market Tuesday after the announcement.

According to the company, the regulator promised PepGen an official letter within 30 days explaining its decision to impose a clinical hold.

“We are disappointed to receive a clinical hold notice on our planned PGN-EDODM1 study in the U.S., and we will work closely with the FDA to lift the hold as quickly as possible,” said PepGen CEO James McArthur in a statement.

PepGen announced positive IND-enabling preclinical data in December for PGN-EDODM1, its investigational oligonucleotide for myotonic dystrophy type 1. DM1 is a genetic disorder affecting an estimated 40,000 people in the U.S. with stiff or contracted muscles, muscle weakness, and cardiac and respiratory abnormalities.

According to PepGen, PGN-EDODM1 can fix more than 60% of mis-splicing events in a murine model of DM1, completely reversing myotonia, the muscle stiffness effect of the disease. The correction was sustained through 24 weeks following a single dose of the therapeutic oligonucleotide.

PepGen already has one candidate in the clinic for Duchenne muscular dystrophy (DMD). The Phase I trial of PGN-EDO51 showed the potential of the company’s enhanced delivery oligonucleotide technology to deliver the candidate therapeutic to the human muscle effectively.

PGN-EDO51 got the green light from Health Canada earlier this month to commence Phase II multiple ascending dose trial of the therapy in DMD patients. This week’s press release confirmed the clinical hold placed on the DM1 asset does not impact the DMD trial in Canada.

Although the announcement sent its stock tumbling, PepGen is sitting on a sufficient nest egg to carry on. The company’s first quarter financials listed its cash runway at $165.4 million at the end of March, enough to fund planned operations into early 2025.

PepGen’s DM1 agent isn’t the only one to face the FDA’s regulatory actions recently. Last fall, the FDA halted clinical trial enrollment of Avidity Biosciences’ Phase I/II trial in AOC 1001 for DM1 after a patient suffered a “serious adverse event.” While the investigator classified the event as drug related, Avidity could not identify a biological link from its treatment to the neurological event and noted AOC 1001 does not cross the blood-brain barrier.

In December, the company announced positive preliminary data from the study with “meaningful DMPK reduction in 100% of participants” after one or two doses of AOC 1001.

The FDA eased the partial clinical hold on AOC 1001 in May, allowing Avidity to double the number of participants in the open-label extension receiving the higher 4mg/kg dose along with new participant enrollment at the 2mg/kg dosing. Data will be used to finalize the pivotal dose used in the Phase III study.

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at [email protected] and on LinkedIn.

Source: BioSpace