Benitec to Present BB-301 Gene Therapy Results at March Conference

Benitec Biopharma Inc. (NASDAQ: BNTC) announced that interim clinical study results from its BB-301 Phase 1b/2a treatment study will be presented at the Muscular Dystrophy Association Clinical & Scientific Conference on March 9, 2026. The late-breaking poster presentation will include 12-month follow-up results for the first four patients who completed Cohort 1, 24-month clinical study results for the first Cohort 1 patient, and interim clinical study results for the first Cohort 2 patient. The study involves patients with Oculopharyngeal Muscular Dystrophy (OPMD) who have moderate dysphagia.

The poster, numbered 501 LB and titled "Durable Responses to Low-Dose BB-301 in Oculopharyngeal Muscular Dystrophy at 12- and 24-months and Improved Depth of Response to High-Dose BB-301," will be displayed during multiple poster sessions throughout the day at the conference in Orlando, Florida. Poster sessions are scheduled from 10:15-10:45 am, 12:00-1:30 pm, 3:30-4:00 pm and 6:00-8:00 pm Eastern Time in the Exhibit Hall.

All four Cohort 1 Completers were formal responders to BB-301, demonstrating durable response to BB-301 at the conclusion of the 12-month statistical follow-up period. At the 24-month post-BB-301 treatment follow-up timepoint, Patient 1 of Cohort 1 continued to demonstrate robust, disease-modifying outcomes. Patient 1 demonstrated deepening improvements in post-swallow pharyngeal residue as compared to the final pre-treatment timepoint and as compared to the 12-month post-treatment follow-up timepoint as assessed by VFSS. Patient 1 also experienced deepening improvements in total dysphagic symptom burden as assessed by the SSQ.

The first Patient in Cohort 2 was safely treated with the higher-dose of BB-301 in the fourth quarter of 2025 and an update on the interim clinical results of Cohort 2 is planned for mid-2026.

BB-301 is a modified AAV9 capsid expressing a bifunctional construct that promotes co-expression of codon-optimized Poly-A Binding Protein Nuclear-1 (PABPN1) and two small inhibitory RNAs against mutant PABPN1. The two siRNAs are modeled into microRNA backbones to silence expression of faulty mutant PABPN1, while allowing expression of the codon-optimized PABPN1 to replace the mutant with a functional version of the protein.

The Company plans to engage with the FDA in mid-2026 to confirm the BB-301 pivotal study design. In November 2025, Fast Track Designation was granted for BB-301 following FDA review of positive interim clinical study results and the proprietary Responder Analysis planned for use in the BB-301 pivotal study. BB-301 has received Orphan Drug Designation from the EMA and Orphan Drug and Fast Track Designations from the FDA.

Benitec Biopharma Inc. is a clinical-stage biotechnology company based in Hayward, California, focused on the advancement of novel genetic medicines. The proprietary "Silence and Replace" DNA-directed RNA interference platform combines RNA interference with gene therapy to create medicines that simultaneously facilitate sustained silencing of disease-causing genes and concomitant delivery of wildtype replacement genes following a single administration of the therapeutic construct.