Neurogene Inc. · NASDAQ:NGNE
Neurogene — Corporate Update (November 2025)
22 slides from Neurogene's corporate update, Nov 12, 2025
Slide 1: NGN-401 Phase 1/2 Interim Data Update
Every Breakthrough BEGINS WITH BELIEF r r t r BE I S IT BELIEF NGN-401 Phase 1/2 Interim Data Update November 2025
Slide 2: Disclaimer: Forward Looking Statements
2 Disclaimer Forward Looking Statements This communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements may discuss goals, intentions and expectations as to future plans, trends, events, results of operations or fina
Slide 3: NGN-401: Setting the Standard for Rett Syndrome Gene Therapy
NGN-401: Setting the Standard for Rett Syndrome Gene Therapy 3Entire presentation includes data cutoff date of October 30, 2025; N=8 for efficacy (ages 4-10 cohort) and N=10 for safety (ages 4-10 and ages > 11 cohorts) ✓ Multidomain improvements ✓ Progressive skill gains over time ✓ Durability of re
Slide 4: A Best-in-Class Gene Therapy for Rett Syndrome Requires Durable, Multidomain Gains
A Best-in-Class Gene Therapy for Rett Syndrome Requires Durable, Multidomain Gains that Grow Over Time 4As of data cutoff date of October 30, 2025 NGN-401 Phase 1/2 Pediatric Data Update 8 Participants included Multidomain Improvements 35 Skills Gained Overall Durable, No Skills Lost Results in Loca
Slide 5: NGN-401 Phase 1/2 Interim Data Summary
NGN-401 Phase 1/2 Interim Data Summary 5
Slide 6: Baseline Characteristics of Phase 1/2 Trial Pediatric Participants
6 Time Post Dosing Pt:1 24 months Pt:2 18 months Pt:3 18 months Pt:4 15 months Pt:5 12 months Pt:6 6 months Pt:7 6 months Pt:8 6 months Age at Dosing 7 4 6 7 6 4 6 8 Baseline CGI-S Score 4 Moderately Ill 5 Markedly Ill 5 Markedly Ill 5 Markedly Ill 5 Markedly Ill 5 Markedly Ill 4 Moderately Ill 4 Mo
Slide 7: Responders in Phase 1/2 Trial Far Exceed Bar of Embolden Primary Endpoint
As of data cutoff date of October 30, 2025 Responders in Phase 1/2 Trial Far Exceed Bar of Embolden Primary Endpoint at 12 Months with Increased Skill Gains Over Time Pt:1 Pt:2 Pt:3 Pt:4 Pt:5 5 of 5 with functional gains 4 of 5 with CGI-I of ≤ 3, all durable - 4 of 5 with > 1 skills Gains in Hand Fu
Slide 8: Participants Dosed in 1H'25 Show Efficacy Prior to 12-month Timepoint
8As of data cutoff date of October 30, 2025 Participants Dosed in 1H’25 Show Efficacy Prior to 12-month Timepoint Pt:6 Pt:7 Pt:8 Gains in Hand Function, Communication, Gross Motor 3 of 3 with functional gains 3 of 3 with CGI-I of ≤ 3 2 of 3 acquired skills Early efficacy observed at 6 months is cons
Slide 9: Early Multidomain Improvements with Skill Gains Increasing Over Time that Remain Durable
Pt:7 6 months post-dose Pt:8 6 months post-dose Pt:4 15 months post-dose Pt:3 18 months post-dose Pt:2 18 months post-dose Pt:1 24 months post-dose Hand Function Gross Motor Function Communication 35 Total Skills Gained* 1 Skill 3 Skills 4 Skills 6 Skills 10 Skills 11 Skills Early Multidomain Improv
Slide 10: Pt:1 Gained Developmental Milestones/Skills Across All Core Domains
Pt:1 Gained 11 Developmental Milestones/Skills Across All Core Domains with Durability out to 24 Months 10 As of data cutoff date of October 30, 2025 *Not included in Embolden developmental milestones/skills list; previously reported skill from other validated scale Images are representative of skil
Slide 11: Pt:2 Gained Developmental Milestones/Skills Across All Core Domains
Pt:2 Gained 10 Developmental Milestones/Skills Across All Core Domains with Durability out to 18 Months 11 As of data cutoff date of October 30, 2025 *Not included in Embolden developmental milestones/skills list; previously reported skills from other validated scales Images are representative of sk
Slide 12: Pt:3 Gained Developmental Milestones/Skills Across All Core Domains
Fine Motor Gross Motor Pt:3 Gained 6 Developmental Milestones/Skills Across All Core Domains with Durability out to 18 Months 12 As of data cutoff date of October 30, 2025 Images are representative of skills Pt:3 Developmental Milestones/Skills Post-NGN-401 Months Post-NGN-401 3 6 9 12 15 18 Used a
Slide 13: Pt:4 Gained Developmental Milestones/Skills Across Core Domains
Pt:4 Gained 4 Developmental Milestones/Skills Across 2 Core Domains with Durability out to 15 Months 13 Fine Motor Baseline: 7 Yrs Old Raking grasp, unable to hold objects Pt:4 Developmental Milestones/Skills Post-NGN-401 Months Post-NGN-401 3 6 9 12 15 Used a pincer grasp (either refined or modifie
Slide 14: Pt:7 Gained Developmental Milestone/Skill at Early Timepoint
Pt:7 Gained 1 Developmental Milestone/Skill at Early Timepoint 14 As of data cutoff date of October 30, 2025 Images are representative of skills Pt:7 Developmental Milestones/Skills Post-NGN-401 Months Post-NGN-401 3 6 Used a spoon/fork to eat without assistance Baseline: 6 Yrs Old Fine Motor Post T
Slide 15: Pt:8 Gained Developmental Milestones/Skills Across Core Domains at Early Timepoint
Pt:8 Gained 3 Developmental Milestones/Skills Across 2 Core Domains at Early Timepoint 15 As of data cutoff date of October 30, 2025 *Not included in Embolden developmental milestones/skills list; previously reported skill from other validated scale Images are representative of skills Pt:7 Developme
Slide 16: Meaningful Changes in Communication, Autonomic, Motor and Hand Function
Communication Can communicate needs & wants, and foster greater social connections Says words with meaning Follows daily routines, e.g., getting ready for school Communicates needs and wants; can ID colors Engages with friends and family; shows affection Starting/ improved communication with use of
Slide 17: Caregiver Quotes
“Sleep improved significantly as she is able to sleep all through the night without any issue.” “Her understanding has improved, especially with me when I ask her to do small tasks, then she will do it immediately almost every time…” “The other day she...ran a couple steps while out…” “She uses both
Slide 18: NGN-401 Remains Generally Well Tolerated at the 1E15 vg Dose Level
• All TEAEs related to NGN-401 have been Grade 1 (mild) or Grade 2 (moderate) in severity; the majority are known potential risks of AAV and have resolved or are resolving • Most participants experienced mild liver enzyme elevations • SAEs (Grade 2) related to abnormal nerve conduction findings occu
Slide 19: Key Upcoming Anticipated Milestones
Key Upcoming Anticipated Milestones 19 Provide regulatory update in 1H:25 regarding Embolden registrational trial Initiate Embolden registrational trial activities Expand clinical trial footprint, more than doubling presence in U.S. Initiate dosing in Embolden registrational trial Announce additiona
Slide 20: Embolden Registrational Trial Overview
Embolden Registrational Trial Overview 20
Slide 21: Key Elements of Embolden Registrational Clinical Trial of NGN-401
Key Elements of Embolden Registrational Clinical Trial of NGN-401 for Rett Syndrome 21 Design: Single-arm, open- label, baseline-controlled trial evaluating NGN-401 at 1E15 vg dose Sample Size: 20 females with Classic Rett syndrome 13 Clinical Sites Age Range: ≥ 3 years First Participant Dosed in Q4
Slide 22: Developmental Milestones/Skills from Rett Syndrome Natural History Study Evaluated in Embolden Trial
28 Developmental Milestones/Skills from Rett Syndrome Natural History Study Being Evaluated in Embolden Trial 22 *U.S. Natural History Study of Rett Syndrome (RNHS), sponsored by NIH, Clinicaltrials.gov identifier: NCT02738281. Accessed from International Rett Syndrome Foundation (IRSF); based on an