Benitec Biopharma: Positive Interim Results for OPMD Gene Therapy BB-301

Benitec Biopharma Inc. (NASDAQ: BNTC) recently announced positive interim data from its Phase 1b/2a clinical trial of BB-301, a novel gene therapy for Oculopharyngeal Muscular Dystrophy (OPMD). The data, presented at the 29th Annual Congress of the World Muscle Society, demonstrated clinically meaningful improvements in swallowing function for two subjects treated with a low dose of BB-301.

The BB-301 Phase 1b/2a study is a single-arm, open-label, sequential, dose-escalation cohort study (NCT06185673) in OPMD patients with dysphagia. The interim clinical study update presented at the World Muscle Society Congress detailed the 9-month (270-day) post-dose results for the first subject and the 6-month (180-day) post-dose results for the second subject, both of whom were safely treated with BB-301.

Key efficacy endpoints included videofluoroscopic swallowing study (VFSS) assessments of Total Pharyngeal Residue (TPR) and the Subject-Reported Outcome Instrument, the Sydney Swallow Questionnaire (SSQ). The post-dose results were compared to the average pre-dose results for each subject during their enrollment in the Benitec-sponsored OPMD Natural History (NH) Study.

Subject 1, who had a more severe baseline dysphagia, experienced clinically meaningful improvements in post-dose SSQ Total Score and SSQ Sub-Scores at Day 270, driven by corresponding reductions in VFSS TPR values. Subject 2, with less severe baseline dysphagia, also showed clinically meaningful improvements in post-dose SSQ Total Score and SSQ Sub-Scores at Day 180, with an SSQ Total Score representative of a normal swallowing profile. This was driven by a corresponding reduction in the frequency of pathologic low-volume sequential swallows.


These data represent the first reported successful improvements in swallow function using a novel gene therapy for OPMD. Subjects enrolled in the NH Study and the BB-301 Phase 1b/2a Clinical Study have been shown to be impacted by excessive accumulation of pharyngeal residue post-swallow and pathologic low-volume sequential swallows.


The positive interim results from the BB-301 Phase 1b/2a study have the potential to accelerate the timeline for further clinical trials and potential approval of BB-301. Long-term effects on quality of life and survival rates for OPMD patients treated with BB-301 could be significant, as dysphagia is a major contributor to morbidity and mortality in OPMD patients.

The competitive landscape for OPMD treatments may shift with the successful development of BB-301, potentially strengthening Benitec's market position. The financial implications for Benitec and its investors could be substantial, as the success of BB-301 could lead to increased market capitalization and potential licensing or partnership opportunities.

In conclusion, the positive interim results from the BB-301 Phase 1b/2a study demonstrate the potential of gene therapy in treating OPMD-related dysphagia. As the clinical development of BB-301 continues, investors should closely monitor the progress of this promising therapy.