Benitec Biopharma Inc. (NASDAQ: BNTC) announced on October 28, 2026, that it has received positive interim results from the Phase 1b/2a first-in-human study (NCT06185673) for its investigational gene therapy BB-301. The company reported that all patients treated with BB-301 across both low and high dose cohorts have been classified as formal responders to the therapy.
The study focuses on patients with Oculopharyngeal Muscular Dystrophy (OPMD), a rare autosomal-dominant degenerative muscle disorder. The company noted that there are currently no approved therapies for the disease, which affects an estimated 15,000 patients in North America, Europe, and Israel. OPMD causes progressive weakness in the pharyngeal muscles, leading to severe swallowing difficulties known as dysphagia.
Benitec evaluated 12-month post-treatment follow-up results for six patients in Cohort 1 (low dose) and available follow-up results for three patients in Cohort 2 (high dose). The results indicate that 100% of patients in Cohort 1 and 100% of patients in Cohort 2 met the statistical criteria for response. Evaluations of dose-related improvements were carried out at the 3-month post-treatment time-point. At this stage, 67% of low-dose patients and 100% of high-dose patients met the statistical criteria for improved throat emptying ability, as assessed by videofluoroscopic evaluation. Similarly, 17% of low-dose patients and 67% of high-dose patients met the criteria for improved functional swallowing capacity, as assessed by the Cold-Water Timed Drinking Test.
Improvements in total Sydney Swallow Questionnaire (SSQ) scores and throat closing ability were observed in both cohorts, with 100% of patients in Cohort 1 and Cohort 2 meeting the statistical criteria for improved total SSQ score at the 3-month mark. The company stated that there have been no Serious Adverse Events reported in any patient treated with BB-301 to date.
BB-301 is a one-time, locally administered gene therapy designed to silence the expression of the mutant PABPN1 gene and replace it with a codon-optimized functional version. The therapy utilizes a proprietary 'Silence and Replace' DNA-directed RNA interference (ddRNAi) platform. BB-301 has received Orphan Drug Designation from the European Medicines Agency (EMA) as well as Orphan Drug and Fast Track Designations from the U.S. Food and Drug Administration (FDA).
The company stated that it remains focused on advancing toward a pivotal study planned for mid-2027. Benitec noted that the results are subject to risks and uncertainties that may cause actual results to differ materially from those anticipated, including the success of clinical trials, patient enrollment, and regulatory approvals.
