Benitec Biopharma : Corporate Presentation, May 2026

Published: 2026-05-15 21:25:05 ET BNTC

Published on 05/15/2026 at 09:25 pm EDT

Durable Responses to Low Dose Investigational Gene Therapy BB-301 in Patients with Oculopharyngeal Muscular Dystrophy with Dysphagia at 12-Months and 24-Months and Improved Depth of Response to High Dose BB-301

American Society of Cell & Gene Therapy May 15, 2026

NASDAQ

BNTC

Oculopharyngeal Muscular Dystrophy (OPMD)

A rare autosomal-dominant degenerative muscle disorder

OPMD is a rare autosomal-dominant

degenerative muscle disorder, caused by a mutation in the poly(A)-binding protein nuclear 1 (PABPN1) gene

PABPN1 is a ubiquitous protein that

controls the length of mRNA poly(A) tails, mRNA export from the nucleus and alternative poly(A) site usage

OPMD ONSET: TYPICAL AGE IS 40s-50s

Eyelid drooping

(ptosis)

Difficulty swallowing

(dysphagia)

and choking during meals

Proximal limb weakness

Patients in North America, Europe and Israel

Progressive dysphagia impacts 97% of OPMD patients and is a severe, life-threatening complication of OPMD which can lead to chronic choking, malnutrition, aspiration

pneumonia and death

BB-301 is the only clinical-stage therapeutic in development designed to treat dysphagia in patients with OPMD

May 2026 Benitec Corporate Overview | Non-Confidential 4

OPMD weakens pharyngeal muscles, causing severe swallowing difficulties

(dysphagia)

Dysphagia leads to choking, malnutrition,

aspiration pneumonia1

Anatomical Structures of the Pharynx and BB-301 Injection Sites

BB-301 is designed to increase muscle mass and function, reducing dysphagia and improving patient outcomes

times per hour a healthy human will spontaneously swallow2

Middle

pharyngeal constrictor

Inferior

pharyngeal constrictor

BB-301

BB-301 is delivered to the pharyngeal constrictor muscles via direct intramuscular injection in the operating room to maximize local benefit and minimize systemic exposure

1. https://www.mayoclinic.org/diseases-conditions/dysphagia/symptoms-causes/syc-20372028 2. Rudney et al. (1995)

May 2026 Benitec Corporate Overview | Non-Confidential 5

BB-301: A Disease-Modifying Genetic Medicine for OPMD-Related Dysphagia

BB-301

AAV9-PL

Muscle

Specific Promoter

coPABPN1

shmiR-17

shmiR-13

BB-301 uses DNA-directed RNA interference (ddRNAi) to simultaneously

SILENCE + REPLACE

T H E

mutant gene

W I T H A

ITR

functional gene

potentially providing a permanent solution with a single administration

Replaces

coPABPN1 is

insensitive to

shRNA

with a healthy gene

Silences

mutant gene

Restoration of functional PABPN1

Strings-Ufombah, et al., Molecular Therapy: Nucleic Acids, Vol. 24, 67-78, June 2021

May 2026 Benitec Corporate Overview | Non-Confidential 7

Clinical Study Design and Key Efficacy Endpoints of the OPMD Natural History Study and the BB-301 Phase 1b/2a First-in-Human Study

OPMD Natural History Study

(26 weeks)

Dosing

(1 Day)

BB-301 Phase 1b/2a

Open-Label Dose Escalation Study (52 weeks)

5 Clinical follow-up visits during which pre-treatment baseline

assessments are carried out for each patient

Natural History Study patients enroll into the

Phase 1b/2a Study

4 Clinical follow-up visits during which post-treatment assessments

are carried out for each patient

23 patients have been enrolled in the OPMD Natural History Study to date

Natural History Study patients may be eligible for the pivotal study

All patients are blinded to their Total SSQ Scores and VFSS (TPR and Sequential Swallowing) assessment results, and the Central Reader for the VFSS assessments is blinded to the SSQ Scores for all patients

The BB-301 Phase 1b/2a Open-Label Dose Escalation Study can enroll up to 30 patients across 3 doses

The primary endpoint is safety, and secondary endpoints focus on qualitative and quantitative assessments of swallowing function.

There have been no treatment-related SAEs in any patient dosed with BB-301 to date.

Clinical results from the first 4 patients of Cohort 1 (1.2e13 vg/patient) who have completed the statistical follow-up period of 12-months post-BB-301 treatment are presented here.

Interim clinical results (3-months post-BB-301 treatment) from the first patient in Cohort 2 (1.8e13 vg/patient) are presented here.

May 2026 Benitec Corporate Overview | Non-Confidential 9

Efficacy assessments were derived from literature-based methods used to assess OPMD dysphagic symptom burden and include patient-reported outcomes, objective anatomic assessments, and functional parameters

The Natural History Study and BB-301 Phase 1b/2a Clinical Study include comprehensive assessments of dysphagia approximately every 3 months

The total dysphagic symptom burden experienced by OPMD patients has several known underlying contributors

Patient-Reported Oral-Pharyngeal Dysphagia via use of a clinically validated 17-question patient reported outcome instrument, Sydney Swallow Questionnaire (SSQ)

The serial assessments of dysphagia facilitated the creation of a multi-component responder analysis which incorporates multiple discrete assessments that holistically assess disease progression and treatment benefit of BB-301

Videofluoroscopic Swallowing Studies (VFSS) of liquids and solids for anatomic and functional assessments of:

Pharyngeal constrictor muscle function via assessment of Pharyngeal Area at Maximum Pharyngeal Constriction (PhAMPC)

Swallowing Efficiency via assessment of post-swallow accumulation of food/liquid material

Total Pharyngeal Residue (TPR)

Normalized Residue Ratio Scale, Valleculae (NRRSv)

Swallowing Effectiveness via assessment of frequency of pathologic sequential swallows (SEQ)

Functional swallowing capacity as measured by the Cold Water Timed Drinking Test (CWDT)

May 2026 Benitec Corporate Overview | Non-Confidential 10

TOTAL RESPONDER SCORING

M A X I M U M S C O R E

5 "Yes" values (one per

measure)

R E S P O N D E R S T A T U S

Achieving ≥2 "Yes" values

(≥40%) qualifies a patient

as a responder

Patient-Reported Oral-Pharyngeal Dysphagia (SSQ)

Criteria: SSQ score must not worsen after treatment

Pharyngeal Constrictor Muscle Function (PhAMPC)

Criteria: Statistical criteria* met in at least 1 of 4 swallowing tasks

Frequency of Pathologic Sequential Swallows (SEQ)

Criteria: At least a 30% decrease in sequential swallows post-treatment

Swallowing Efficiency (NRRSv or TPR)

Criteria: Statistical criteria* met in at least 1 of 8 swallowing tasks

Functional Swallowing Capacity (CWDT)

Criteria: Statistical criteria* met for the cold-water timed drinking test

*Formal statistical criteria were submitted to FDA over the course of the interactive process that supported the grant of Fast Track Designation for BB-301

May 2026 Benitec Corporate Overview | Non-Confidential 11

BB-301 Phase 1b Study: Cohort 1 Study Completers

Completers are Patients that have reached the 12-month post-BB-301-treatment assessment time-point

May 2026 Benitec Corporate Overview | Non-Confidential 13

BB-301 Phase 1b Study: Long Term Efficacy Trends for Cohort 1

Patient 1 of Cohort 1 experienced deepening improvements in both post-swallow pharyngeal residue and total dysphagic symptom burden 24-months post-BB-301 treatment

May 2026 Benitec Corporate Overview | Non-Confidential 15

BB-301 Phase 1b Study: Cohort 1 Dose vs. Cohort 2 Dose

Preliminary comparisons of efficacy trends

Significant Improvements in Throat Closure, Post-Swallow Pharyngeal Residue, and Total Dysphagic

Symptom Burden Observed Following High Dose BB-301 Treatment

Patient A (Cohort 1) and Patient B (Cohort 2) had comparable baseline functional and anatomical deficits.

Patient B (Cohort 2) was safely treated with BB-301.

When comparing 3-month post-treatment data for both Patient A and Patient B, Patient B demonstrated improved depth of response to high dose BB-301.

Preliminary interim clinical results demonstrate improved depth of response to high dose BB-301 at the 3-month post-treatment timepoint

May 2026 Benitec Corporate Overview | Non-Confidential 17

May 2026 Benitec Corporate Overview | Non-Confidential 18

P H A S E 1 b / 2 a C L I N I C A L E F F I C A C Y

ROBUST RESPONSES TO BB-301 IN COHORT 1 AND COHORT 2

MEANINGFUL IMPROVEMENTS POST-BB-301 ADMINISTRATION ACROSS KEY ENDPOINTS

Improved patient reported outcome

Improved throat closure

Reduced pharyngeal residue

Improved functional swallowing capacity

S A F E T Y

NO TREATMENT-RELATED SEVERE

ADVERSE EVENTS

R E G U L A T O R Y

FAST TRACK DESIGNATION (FDA)

ORPHAN DRUG DESIGNATION (FDA &

EMA)

May 2026 Benitec Corporate Overview | Non-Confidential 19

One Platform. One Dose.

Potentially Transformative Outcomes.

THANK YOU!

w w w. be ni tec . c om

Disclaimer

Benitec Biopharma Inc. published this content on May 16, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on May 16, 2026 at 01:24 UTC.