Regenxbio Inc. · NASDAQ:RGNX
Regenxbio — AAN 2025
12 slides from Regenxbio's conference presentation, 2025
Slide 1: RGX-202 gene therapy for Duchenne muscular dystrophy: interim clinical data
RGX-202, an investigational gene therapy for the treatment of Duchenne muscular dystrophy: interim clinical data Aravindhan Veerapandiyan, M.D. Arkansas Children’s Hospital RGX-202 is an investigational product that has not been approved by the FDA. No conclusions regarding safety and efficacy can b
Slide 2: RGX-202 is the only microdystrophin gene therapy with C-Terminal domain
RGX-202 is the only microdystrophin gene therapy with the functional elements of the C-Terminal (CT) domain found in naturally occurring dystrophin AAV Promoter Transgene Serotype REGENXBIO 8 Spc5-12 ABD1 H1 R1 R2 R3 H3 R24 H4 CR CT RGX-202 Sarepta1 rh Elevidys® MHCK7 ABD1 H1 R1 R2 R3 H2 R24 H4 CR 7
Slide 3: Phase I/II Trial Overview
Phase I/II Trial Overview Key Eligibility Criteria • Boys aged 1 to <12yo at screening • Genetically confirmed DMD (mutations in exons 18 and above) • No pre-existing antibodies to the gene therapy (AAV8 capsid) 1 to <4yo 4+ yo 10 meter walk without assistance 100 meter walk without assistance Stabl
Slide 4: Phase I/II Trial Design
Phase I/II Trial Design Administration and Assessments Timeline Baseline Treatment Evaluation (Months) Long Term Follow-up Primary Endpoint Biomarker Safety Endpoint RGX–202 3 6 9 12 5 Years Administration months Immunosuppression Safety is assessed continuously throughout the trial Muscle biopsy Al
Slide 5: Key Baseline Demographics
Phase I/II, Interim Data Key Baseline Demographics Variable Mean Dose Level 1 Dose Level 2 (range) 1x1014 GC/kg 2x1014 GC/kg Age range at screening 4-11 1-3 4-11 (number dosed) (n = 3) (n = 2) (n = 7) Age at Dosing (yrs) 7.1 3.0 8.7 (4.4-10.5) (2.3, 3.7) (5.8-12.1) Weight (kg) 24.3 11.4 26.2 (17.8-2
Slide 6: Interim Safety
Phase I/II, Interim Data Interim Safety Dose Level 2 Dose Level 1 Dose Level 2 RGX-202 Treatment-Emergent Dose Evaluation / Total Dose Evaluation Younger Boys Adverse Events Expansion n = 12 (1x1014 GC/kg) (2x1014 GC/kg) (2x1014 GC/kg) Age Range 4-11 1-3 4-11 All Age Ranges (number dosed) (n = 3) (n
Slide 7: Biomarkers Support Consistent Robust Expression, Transduction, and Sarcolemmal Localization
Phase I/II, Interim Data Biomarkers Support Consistent Robust Expression, Transduction, and Sarcolemmal Localization of RGX-202 Microdystrophin RGX-202 Mean at 12 Weeks Dose Level 1 Dose Level 2 Microdystrophin (min, max) 1x1014 GC/kg 2x1014 GC/kg DL 2, 12 weeks Age range at 4-7 8-11 1-3 4-7 8-11 sc
Slide 8: Pivotal & Dose Level Participants Demonstrate Improvement in Function and Exceed External Controls
Pivotal & Dose Level 1 Participants Demonstrate Improvement in Function and Exceed External Controls Timed Function Tests NSAA Mean Change in Time (Seconds) -2.0 TTStand 10MWR TTClimb ∆ 4.0 Mean Change in NSAA -1.5 ∆ -2.9 ∆ -1.1 ∆ -1.8 6 -1.0 5 Dose N=3 4 Level -0.5 N=3 N=2 3 1 0.0 2 N=18 N=3 12 mo
Slide 9: AFFINITY DUCHENNE Phase III Trial: Open & Enrolling
AFFINITY DUCHENNE Phase III Trial: Open & Enrolling Key Eligibility Criteria (n ≈ 30) • Boys aged 1+ years at screening • Genetically confirmed DMD (all mutations except those with deletions or point mutations in exons 8, 9, and/or 10) • No pre-existing antibodies to the gene therapy (AAV8 capsid) 1
Slide 10: AFFINITY DUCHENNE Pivotal Trial Design
AFFINITY DUCHENNE Pivotal Trial Design A multi-center, open-label pivotal trial Administration and Assessments Timeline Baseline Treatment Evaluation (Months) Long Term Follow-up Primary Endpoint Functional RGX-202 microdystrophin levels Endpoint RGX–202 3 6 9 12 18 24 5 Years Administration months
Slide 11: AFFINITY DUCHENNE: Phase I/II Interim Summary
AFFINITY DUCHENNE: Phase I/II Interim Summary Phase III trial open and enrolling RGX-202 has been well-tolerated in 12 patients across both dose levels with no SAEs or AESIs1 Biomarkers support consistent robust expression, transduction, and sarcolemmal localization of RGX-202 microdystrophin1 Parti
Slide 12: Acknowledgements
Acknowledgements AFFINITY DUCHENNE Participants and their Families The AFFINITY DUCHENNE Investigators • Amy Harper, M.D., Children’s Hospital of Richmond at Virginia Commonwealth University REGENXBIO • Susan Iannacone, M.D., The University of Texas Southwestern Medical Center Nidal Boulos Michelle