Solid Biosciences Inc. · NASDAQ:SLDB

Solid Biosciences — Investor Presentation (September 2026)

18 slides from Solid Biosciences's investor presentation, September 2026

1. Slide 1: POLARIS-101 Next Gen Muscle Tropic AAV

   POLARIS-101 Next Gen Muscle Tropic AAV Solid Bio, Shaping the Future of Gene Therapy © 2026 Solid Biosciences – Non-Confidential

2. Slide 2: Cautionary Note Regarding Forward Looking Statements and Disclaimer

   Cautionary Note Regarding Forward Looking Statements and Disclaimer This presentation contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding future expectations, plans and prospects for the company; the ability

3. Slide 3: POLARIS-101 is a Next-Generation Capsid With Improved Muscle Tropism

   POLARIS-101 is a Next-Generation Capsid With Improved Muscle Tropism, Enabling Safe and Effective Systemic Administration POLARIS-101 ,a offers potential for transformative efficiency with effective skeletal muscle and cardiac tissue targeting and lower toxicity risks1,2,3,4 High-efficiency transduc

4. Slide 4: Accelerating Innovation: Solid's AAV Gene Therapy Development Kit Available for Partnership

   Accelerating Innovation: Solid’s AAV Gene Therapy Development Kit Available for Partnership GROWING BODY OF ROBUST LEADING-EDGE CLINICAL DATA PRECLINICAL DATA CMC TECHNOLOGY Muscle biopsies at Mouse: Biodistribution and POLARIS-101 RepCap Day 90 and Day 360 expression in multiple plasmid provided fr

5. Slide 5: SOLID INSIDE: Saving Partners Time, Money and Risk

   SOLID INSIDE: At Multiple Stages Along The Way Solid Can Save Partners Time, Money and Risk Solid Inside Offers Partners Multiple Ways to Save Time, money and risk across gene therapy drug development CAPITAL-EFFICIENT LICENSE MUSCLE-DIRECTED CAPSID IND RIGHT OF REFERENCE ORION Buffer System • Low u

6. Slide 6: POLARIS-101: A Novel Capsid Showing Promising Clinical Signals in Duchenne

   POLARIS-101 : A Novel Capsid Showing Promising Clinical Signals in Duchenne Muscular Dystrophy SGT-003 Solid’s next-gen, investigational microdystrophin gene transfer therapy that uses POLARIS-101 INSPIRE DUCHENNE Phase 1/2 Clinical Study Overview Heart • Single 1.0×1014 vg/kg IV dose of SGT-003 Ove

7. Slide 7: POLARIS-101 Enhances Muscle Targeting Through Multivalent RGD Motif

   POLARIS-101 Enhances Muscle Targeting Through Novel Integration of a Multivalent RGD Motif1,2 POLARIS-101 Proposed Mechanism of Action POLARIS-101 was engineered to include an RGD motif inserted into the R Basal lamina Integrin VR-VIII loop of AAV9, resulting in up to G D 60 copies of the peptide di

8. Slide 8: POLARIS-101 Shows Higher Skeletal and Cardiac Muscle Biodistribution vs AAV9

   POLARIS-101 Shows Higher Skeletal and Cardiac Muscle Biodistribution vs AAV9 in Mouse and NHPs Biodistribution in Isolated Tissues Biodistribution in Isolated Tissues (Day 28 Post-dose)a,b (Day 28 Post-dose)a,c POLARIS-101 AAV9 POLARIS-101 AAV9 QUADRICEPS HEART SKELETAL MUSCLE CARDIAC MUSCLE 3.7x 6.

9. Slide 9: POLARIS-101 Demonstrates High-Efficiency Expression vs AAV9 in NHPs and Human Cardiomyocytes

   POLARIS-101 Demonstrates High-Efficiency Expression vs AAV9 in NHPs and Human Cardiomyocytes Expression Efficiency Expression Efficiency (Luciferase Activity in NHPs)a,b (Luciferase Activity In Vitro) POLARIS-101 AAV9 POLARIS-101 AAV9 SKELETAL MUSCLE CARDIAC MUSCLE HUMAN DUCHENNE HEALTHY iPSC-DERIVE

10. Slide 10: Human Trial Supports Preclinical Data Showing Reduced Liver Biodistribution

    Human Phase 1/2 INSPIRE DUCHENNE Trial Supports Preclinical Data Showing Reduced Liver Biodistribution of POLARIS-101 AAV Biodistribution to Liver1 POLARIS-101 AAV9 Liver Biomarkers in Participants Dosed Using POLARIS-101 2,b,c,d Fold Change vs AAV9 Fold Change vs AAV9 2.0 1.5 ALT AST GGT 1.5 1.0 15

11. Slide 11: Enhanced Kinetics Enabling Rapid Expression and Optimal Clearance Timing

    POLARIS-101 Exhibits Enhanced Kinetics Enabling Rapid Expression vs AAV9 and AAVrh74 and Optimal Clearance Timing Luciferase Activity (Whole Body IVIS)1 Mean Clearance of POLARIS-101TM2 Total Flux (p/s)/µg) Days post-dose POLARIS-101 expression detected 2 days post-dose, Rapid clearance of POLARIS-1

12. Slide 12: Leads to Greater Protein Expression vs AAVrh74 in NHPs

    POLARIS-101 Leads to Greater Protein Expression vs AAVrh74 in NHPs Expression Efficiency (LCMS - CK8-Microdystrophin in NHPs) Dose 1.0×1014 vg/kg1,a POLARIS-101 AAVrh74 HEARTb QUADRICEPSb 6x 5 4x 6 5 Fold Change vs AAV9 Fold Change vs AAV9 4 4 3 3 2 2 1 1 0 0 POLARIS-101 AAV-SLB101 AAVrh74 POLARIS-1

13. Slide 13: Redosing Potential: Low NAb Titers After AAVrh74 Dosing

    Redosing Potential: POLARIS-101 Demonstrates Low NAb Titers After AAVrh74 Dosing in Multiple Species Assessment of NAbs After AAVrh74 Dosing Longitudinal Assessment Day 30 Assessment of NAb Titers in Humans Dosed With of POLARIS-101 NAbs after rh741 POLARIS-101 NAbs after rh741 AAVrh742 Days posttre

14. Slide 14: Solid's Manufacturing Platform

    Solid's Manufacturing Platform 1 © 2026 Solid Biosciences – Non-Confidential

15. Slide 15: Solid's Dual Plasmid Design Delivers a Significant Yield Increase

    Solid’s Dual Plasmid Design Delivers a Significant Yield Increase Compared to Standard Triple Plasmid Transfection Solid Dual Plasmid Design Relative Yield Improvement Using Solid Dual Plasmid vs 3 Plasmid System* x x x x x x x 1.6-2.8x increase in upstream yields with Solid’s dual plasmid independe

16. Slide 16: Manufacturing Platform Potential to Enhance Safety and Reduce CoGS

    By Increasing Yields and Purity, Solid’s Manufacturing Platform Has The Potential to Further Enhance Safety and Reduce CoGS High, consistent Efficient full Scalable to 500L yield & recovery capsid with identical across sites and enrichment performance scales >200 operating parameters defined between

17. Slide 17: Pioneering Best Practices to Continuously Innovate in CMC Excellence

    Pioneering Best Practices to Continuously Innovate and Stay at the Forefront of CMC Excellence Solid Platform Improvements >Up to100x Platform yields are consistently high independent of capsid Improvement in Platform Yield or GOI (Platform iteration 4) Since PD Work Began Upstream Yield (vg/mL- ddP

18. Slide 18: Thank you

    Thank you Please Contact [email protected] For Additional Information © 2025 Solid Biosciences - Confidential

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