Slide 1: SAT-3247 KOL Event
© 2025 Satellos Bioscience SAT-3247 KOL Event Unmet Need & Current Treatment Landscape for Duchenne Muscular Dystrophy Feb. 24, 2026 R E G E N E R AT I N G M U S C L E F R O M W I T H I N T M
Slide 2: Legal Disclaimers
© 2025 Satellos Bioscience Legal Disclaimers Certain statements in this presentation are “forward-looking statements” under applicable securities laws. Any The information contained herein is subject to change without statements that express or involve discussions with respect to predictions, expect
Slide 3: Agenda
© 2025 Satellos Bioscience Agenda Welcome Frank Gleeson Co-founder & Chief Executive Officer, Satellos Duchenne and the Need for Additional Therapeutic Approaches Dr. Kevin M. Flanigan Wolfe Foundation Endowed Chair in Neuromuscular Research, Nationwide Children’s Hospital; Professor of Pediatrics &
Slide 4: Agenda
© 2025 Satellos Bioscience Agenda Duchenne and the Need for Additional Therapeutic Approaches Dr. Kevin M. Flanigan Wolfe Foundation Endowed Chair in Neuromuscular Research, Nationwide Children’s Hospital; Professor of Pediatrics & Neurology, Ohio State University College of Medicine
Slide 5: Duchenne Muscular Dystrophy and the Need for Additional Therapeutic Approaches
Duchenne Muscular Dystrophy and the Need for Additional Therapeutic Approaches Kevin M. Flanigan, MD Director, Center for Gene Therapy Robert F. & Edgar T. Wolfe Foundation Endowed Chair in Neuromuscular Research Director, NCH Wellstone Muscular Dystrophy Specialized Research Center Nationwide Child
Slide 6: Financial Disclosure
Financial Disclosure • Clinical trial support: Sarepta, Dyne, Avidity, Ultragenyx, Solid • Advisory boards: Armatus, Encoded, Insmed, Dyne, Solid, Precision Biosciences • Past Royalties: stellas ………………..……………………………………………………………………………………………………………………………………..
Slide 7: The Dystrophin Gene (A) and Protein (B)
The Dystrophin Gene (A) and Protein (B) Forum Kamdar and Daniel J. Garry JACC 2016;67:2533-2546
Slide 8: Dystrophinopathies: Clinical Categorization
Dystrophinopathies: Clinical Categorization • DMD: • BMD: – Onset age 3-5 – Classic definition: loss of ambulation > age 12 – Pelvic girdle weakness – Alternatively: – Tight heel cords • “intermediate muscular – CK 50-100X normal dystrophy” for loss of – Loss of ambulation by age 12 ambulation ages
Slide 9: Dystrophin Mutations
Dystrophin Mutations • Dystrophin gene (DMD) on Xp21.1 is huge: – 2.4 million base pairs – 79 exons and 8 promoters • Large deletions (≥ 1 exon) account for ~65% of DMD/BMD patients • ~5% have duplications • ~15% of boys have nonsense mutations • Remainder are frameshifting insertions/deletions, spl
Slide 10: Dystrophin Mutations and the Reading Frame Rule: Duchenne vs Becker
Dystrophin Mutations and the Reading Frame Rule: Duchenne vs Becker The reading frame rule: • Mutations that maintain an open mRNA reading frame (“in-frame mutations”) will result in translation of a protein with partial function (Becker) • Those that ablate the reading frame (“out-of-frame”) will r
Slide 11: Microdystrophin: Derived from Clinical Observation
Microdystrophin: Derived from Clinical Observation • Deletion of 46% of protein (exons 17-48) England et al, Nature 343; 180–182 (1990) • Ambulant to at least age 61 Davies and Vogt, Neuromuscul Disord 2024 Jun:39:5-9.
Slide 12: Delandistrogene moxeparvovec: Improvements in function at years post-treatment
Delandistrogene moxeparvovec: Improvements in function at 2 years post-treatment (EMBARK trial) Mendell et al, Neurol Ther. 2026 Jan 10. doi: 10.1007/s40120-025-00879-8
Slide 13: Not all BMD-associated dystrophin proteins will have the same functional outcome
15% N B D D B D B N 140% Not all BMD-associated dystrophin proteins will have the same functional outcome. LOA: 70 yrs mid-20s • Amount of internally-deleted dystrophin alone is insufficient to predict outcome.
Slide 14: Not All Boys with Out-of-frame Mutations Will Have the Same Outcomes
Not All Boys with Out-of-frame Mutations Will Have the Same Outcomes Wang et al, Hum Mutat 2018 Sep;39(9):1193-1202
Slide 15: What Can Account for These Differences?
What Can Account for These Differences? • Multiple pathways of pathogenesis And therefore • Multiple potential genes relevant as potential modifiers of disease Chang et al, J Neurol 2023 270:3733–3749
Slide 16: One Example: Protective Genotype Associated With the LTBP4 Gene
One Example: There is a Protective Genotype Associated With the LTBP4 Gene • May account for differences Mean age of ambulatory loss for “IAAM” versus other haplotypes: between brothers • In steroid-treated patients: 12.5 ± 3.3 years vs. 10.7 ± 2.1 years • In steroid-naïve patients: 11.2 ± 2.7 vs. 9
Slide 17: The rs2061566 SNP alters an enhancer linked to PARD6G
The rs2061566 SNP alters an enhancer linked to PARD6G Eur J Hum Genet. 2023 Jun;31(6):663-673
Slide 18: Six Novel Candidate Gene Modifiers
Six Novel Candidate Gene Modifiers Chromosome Gene Function Plausible role maintaining genome integrity and chromosomal stability 2 ETAA1 activating protein for ATR of the muscle stem cell population may dictate a switch between a propensity of muscles to 4 GALNTL6 O-GalNAc transferase be predispose
Slide 19: PARD6 is Implicated in Asymmetric Satellite Cell Division
PARD6 is Implicated in Asymmetric Satellite Cell Division Promotion of asymmetric cell division and production of myogenic cells = Objective of SAT-3247 Wang et al, Cell Stem Cell. 2019 Mar 7;24(3):419-432.e6.
Slide 20: Where Does DMD Therapy Stand Today?
Where Does DMD Therapy Stand Today? • Corticosteroids and related steroids • Provide benefit in sustaining ambulation, with significant side effects • AAV-delivered microdystrophin gene therapy • One is approved and others are in trials, but not all boys can receive it • AAV antibody positivity • Sp
Slide 21: Ongoing Therapeutic Needs in DMD
Ongoing Therapeutic Needs in DMD: Therapies that: • Address other pathways of pathogenesis, including inflammation • Improve regenerative capacity of or reduce histopathology of muscle • Are suitable as add-on or “cocktail” therapies following dystrophin (or microdystrophin) restoration ………………..…………
Slide 22: Agenda
© 2025 Satellos Bioscience Agenda The Science Behind SAT-3247 Dr. Michael Rudnicki Co-founder & Chief Discovery Officer, Satellos; Senior Scientist & Director, Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute
Slide 23: Muscle Regeneration Primer
© 2025 Satellos Bioscience Muscle Regeneration Primer
Slide 24: Skeletal Muscle is a Highly Regenerative Tissue
© 2025 Satellos Bioscience Skeletal Muscle is a Highly Regenerative Tissue Healthy muscle Injury (toxin) Cell proliferation Cell maturation Repaired muscle Day 0 Day 5 Day 10 Day 20 Myotube Myocyte Satellite Cell Myoblast Stem Cell 24
Slide 25: Skeletal Muscle is a Highly Regenerative Tissue in People!
© 2025 Satellos Bioscience Skeletal Muscle is a Highly Regenerative Tissue in People! Healthy muscle Electrically stimulated injury Repaired muscle 7 days post injury 30 days post injury (images enhanced from Mackey et al. 2016 for clarity and contrast using AI) 25
Slide 26: In Duchenne, Muscle Regeneration Loses the Battle With Constant Degeneration
© 2025 Satellos Bioscience In Duchenne, Muscle Regeneration Loses the Battle With Constant Degeneration, Failing to Maintain Muscle Healthy Myopathic changes Fatty replacement Fibrosis Early stage Mid stage Late stage 26
Slide 27: Why Does Regeneration Fail in Duchenne?
© 2025 Satellos Bioscience Why Does Regeneration Fail in Duchenne?
Slide 28: Regeneration is Driven by Muscle Stem Cells
© 2025 Satellos Bioscience Regeneration is Driven by Muscle Stem Cells Stem cell division takes place on myofibers Stem Cell Division Key Terms Expansion ***Regeneration*** 1. Symmetric cell division: expanding the stem cell pool 2. Asymmetric cell division: producing new muscle tissue and maintaini
Slide 29: Core Discovery: Asymmetric Cell Division is Regulated by Dystrophin
© 2025 Satellos Bioscience Core Discovery: Asymmetric Cell Division (Regeneration) is Regulated by Dystrophin 29
Slide 30: Core Discovery: Asymmetric Cell Division is Impaired in Duchenne
© 2025 Satellos Bioscience Core Discovery: Asymmetric Cell Division (Regeneration) is Impaired in Duchenne 30
Slide 31: Core Discovery: Asymmetric Cell Division Rescued via Inhibition of AAK1
© 2025 Satellos Bioscience Core Discovery: Asymmetric Cell Division (Regeneration) Can Be Functionally Rescued via Inhibition of AAK1 31
Slide 32: SAT-3247 Polarizes Notch Signalling Inside of Duchenne Muscle Stem Cells
© 2025 Satellos Bioscience SAT-3247 Polarizes Notch Signalling Inside of Duchenne Muscle Stem Cells Resulting in Increased Rates of Asymmetric Division Mdx muscle stem cells Non-polarized Polarized 32
Slide 33: What did Satellos discover?
© 2025 Satellos Bioscience What did Satellos discover? 1. Regeneration is regulated by dystrophin 2. Regeneration is impaired in Duchenne, due to loss of dystrophin 3. Regeneration can be functionally rescued via inhibition of AAK1, even in the absence of dystrophin SAT-3247 enables the natural musc
Slide 34: Preclinical Highlights
© 2025 Satellos Bioscience Preclinical Highlights
Slide 35: Enhancing Progenitor Production Through Increased Asymmetric Division Improves Muscle Strength
© 2025 Satellos Bioscience Enhancing Progenitor Production Through Increased Asymmetric Division Leads to Improved Muscle Strength 35
Slide 36: SAT-3247 Treatment Shows Muscle Regeneration in Canine Model of DMD
© 2025 Satellos Bioscience SAT-3247 Treatment Shows Muscle Regeneration in Canine Model of DMD 500um 500um SAT-3247 Study SAT-3247 Study Healthy Age-Matched DMD Animal / Pre-Treatment DMD Animal / Post-Treatment Non-DMD Comparator Bicep Femoris Bicep Femoris Bicep Femoris 60 mg oral dose | 4x/wk | 4
Slide 37: SAT-3247 Treatment Restores Muscle Strength in Canine Model of DMD
© 2025 Satellos Bioscience SAT-3247 Treatment Restores Muscle Strength in Canine Model of DMD Study Overview SAT-3247 treated vs. historical controls1 Flexion Tetanic Torque 2 DMD dogs: each ~9 mos. of age at start of study Oral dosing with SAT- N/kg 3247: 1x per day, 60 mg 4 days on, 3 days
Slide 38: Agenda
© 2025 Satellos Bioscience Agenda SAT-3247 Clinical Development Overview Dr. Wildon Farwell Chief Medical Officer, Satellos
Slide 39: SAT-3247 Aims to Enhance Muscle Regeneration and Improve Function
© 2025 Satellos Bioscience SAT-3247 Aims to Enhance Muscle Regeneration and Improve Function Approximately 12,000 boys or young men currently live with DMD in the US Genetic approaches to DMD Satellos approach to DMD Administered by infusion or injection Oral, once-daily pill Gene therapy (DNA
Slide 40: SAT-3247 Phase 1 First-in-Human Clinical Trial
© 2025 Satellos Bioscience SAT-3247 Phase 1 First-in-Human Clinical Trial Ph 1a: Healthy Volunteers (n=72) Ph 1b: DMD Adults SAD* Study MAD* Study 28-day, Open-Label Study 10 - 400 mg 60 - 240 mg 60 mg daily dose, weekdays only for 4 weeks 5 cohorts of 8 4 cohorts of 8 5 patients enrolle
Slide 41: SAT-3247 Was Safe and Achieved Target PK in Healthy Volunteers
© 2025 Satellos Bioscience SAT-3247 Was Safe and Achieved Target PK in Healthy Volunteers Safety Profile PK Profile AE Category Part A Part B Part C (n=40) (n=32) (n=8) Any TEAE 9 18 4 Any related 1a 2b 0 TEAE Any serious 0 0 0 TEAE Any related 0 0 0 serious TEAE Any TEAE 0 1c 0 leading to withdrawa
Slide 42: SAT-3247 Was Safe and Achieved Target PK in Adults with DMD
© 2025 Satellos Bioscience SAT-3247 Was Safe and Achieved Target PK in Adults with DMD 5 adults with DMD ages 20 to 27 years, all receiving steroid therapy Safety Profile PK Profile AE Category Part D (n=5) Any TEAE 4 Any related TEAE 2d Any serious TEAE 2e Any related serious 0 TEAE Any TEAE leadin
Slide 43: SAT-3247: Grip Strength Shows Encouraging Benefit in Days
© 2025 Satellos Bioscience SAT-3247: Grip Strength Shows Encouraging Benefit in 28 Days 5.8% Increase in 118.6% and 97.9% Increases in Predicted Forced Vital Capacity (FVC) Grip Strength in Dominant and Non-Dominant hands Mean change Individual Dominant Hand Non-Dominant Hand +5.8% Patients n=4 n=4
Slide 44: Increased Grip Strength Exceeds Results Seen in Natural History
© 2025 Satellos Bioscience Increased Grip Strength with SAT-3247 Treatment Exceeds Results Seen in Natural History Duchenne natural history a SAT-3247 overlay with natural history IMPROVEMENT Improvement with SAT-3247 beyond what is reported for natural history Absolute grip strength is consiste
Slide 45: Grip Strength Improvements Correlate with Cmax and Creatinine Levels
© 2025 Satellos Bioscience Grip Strength Improvements Correlate with Cmax and Creatinine Levels Supports rationale that results seen are drug related Maximum Grip Strength vs Cmax Maximum Grip Strength vs Baseline Creatinine Spearmen correlations: Spearmen correlations: Dominant hand – 0.9 Dominant
Slide 46: Emerging Biomarker Insights in DMD Following SAT-3247 Treatment
© 2025 Satellos Bioscience Emerging Biomarker Insights in DMD Following SAT-3247 Treatment
Slide 47: Broad Proteomic Profiling Enables Assessment of Multiple Biological Pathways
© 2025 Satellos Bioscience Broad Proteomic Profiling Enables Assessment of Multiple Biological Pathways Measures thousands of circulating proteins simultaneously Captures coordinated biological signals beyond single biomarkers Provides relative changes over time Used by Satellos to explore t
Slide 48: Consistent Declines Across Established DMD Biomarkers
© 2025 Satellos Bioscience Consistent Declines Across Established DMD Biomarkers Reductions in classical DMD biomarkers of muscle injury known to correlate with CK (ie. AK1, CA3, MB, ENO3) after 15 days of dosing Reduction in recently identified potential biomarkers of muscle injury (ie. ANKRD2)
Slide 49: Current Clinical Trials to Evaluate SAT-3247 in People with DMD
© 2025 Satellos Bioscience Current Clinical Trials to Evaluate SAT-3247 in People with DMD TRAILHEAD (LT-001) BASECAMP (CL-201) 51 ambulatory DMD participants aged ≥ 7 and Participants Up to 30 adults with DMD >=18 years < 10 years of age Will assess the long-term safety, Will study 60 and 120 mg of
Slide 50: 2026 Clinical Trial Catalysts: Quarterly Momentum
© 2025 Satellos Bioscience 2026 Clinical Trial Catalysts: Quarterly Momentum Q1 Q2 Q3 Q4 TRAILHEAD: Grip & FVC, TRAILHEAD: Grip & FVC, TRAILHEAD: Grip & FVC, TRAILHEAD: Grip & FVC, Biomarkers Biomarkers, MRI Biomarkers Biomarkers, MRI BASECAMP: Site initiation & BASECAMP: Interim clinica
Slide 51: Q&A
© 2025 Satellos Bioscience Agenda Q&A
Slide 52: Reimagine
Reimagine how muscle degeneration is treated. Regenerate with small molecule medicines. Realize the next horizon to improve lives.