MD trial update: 5 OPMD patients safely treated with gene therapy
Benitec testing BB-301 for disease type affecting face, throat muscles
Five people with oculopharyngeal muscular dystrophy (OPMD) — a type of muscular dystrophy marked by muscle weakness affecting the face and throat — have thus far been treated with the gene therapy candidate BB-301 in an ongoing clinical trial, treatment developer Benitec Biopharma said in a company update.
According to Benitec, the fourth and fifth patients treated — who were given the gene therapy in December and February, respectively — were both safely administered the treatment at its low dose. The company said it expects to give a sixth patient the low dose of BB-301 in the coming months.
Later this year, Benitec plans to start testing a higher dose of BB-301 in OPMD patients in the trial, underway at a single site in New York City.
“We remain highly optimistic about the potential for continued benefit in [patients] enrolled in the ongoing clinical study,” Jerel A. Banks, MD, PhD, executive chairman and CEO of Benitec, said in a press release detailing the company’s financial results thus far in 2025 and providing an operational update.
“We look forward to enrolling additional subjects at the low dose and, this year, at the next, higher dose of BB-301,” Banks added.
Gene therapy for OPMD aims to ease swallowing difficulties in patients
The Phase 1b/2a clinical trial (NCT06185673), set to enroll an estimated 30 people with OPMD, is now actively recruiting participants. The trial is open to patients with evidence of moderate swallowing difficulties who have been followed for at least six months as part of a separate study that Benitec is now running. That study is collecting data on how OPMD progresses in the absence of treatment.
“We continue to be extremely grateful for the strong support of the [participants] and their families and for their continued participation in the BB-301 clinical development program,” Banks said.
In 2024 the interim clinical study data demonstrated durable, clinically meaningful improvements in swallowing function for the first [participants] safely treated with BB-301.
OPMD usually manifests in middle age and is characterized by weakness of muscles around the face and throat. Dysphagia, referring to difficulty swallowing, is a common symptom.
The main goals of the clinical trial are to assess BB-301’s safety and its effects on patients’ swallowing function. Interim data from the first two participants in the trial, presented last year, indicated that BB-301 was generally safe and that the treatment improved swallowing abilities.
“In 2024 the interim clinical study data demonstrated durable, clinically meaningful improvements in swallowing function for the first [participants] safely treated with BB-301,” Banks said.
OPMD is caused by mutations in the PABPN1 gene. BB-301 uses a type of silence and replace strategy developed by Benitec. Essentially, the therapy aims to inactivate the mutated version of the PABPN1 gene while also providing patients’ cells with a healthy version of the gene.
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