Slide 1: FORTIFY Phase 3 Interim Analysis Topline Results of BBP-418 in LGMD2I/R9
FORTIFY Phase 3 Interim Analysis Topline Results of BBP-418 in LGMD2I/R9 October 27, 2025 BBP-418 is an investigational therapy and has not been Seamus approved for use by any regulatory agency. Living with LGMD2I/R9
Slide 2: Forward Looking Statements and Disclaimer
Forward Looking Statements and Disclaimer Statements made or presented in this Presentation may include statements that are not historical fact and are considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities
Slide 3: Agenda
Agenda Neil Kumar, PhD 1 Opening remarks Chief Executive Officer, BridgeBio Christine Siu 2 Introduction Chief Executive Officer, ML Bio Solutions, a BridgeBio Company FORTIFY Phase 3 interim Douglas Sproule, MD, MSc 3 analysis topline results Chief Medical Officer, ML Bio Solutions, a BridgeBio Com
Slide 4: A sincere THANK YOU to patients, families, advocates, investigators
BBP-418 for Limb-Girdle Muscular Dystrophy Type 2I/R9 (LGMD2I/R9) A sincere THANK YOU to patients, families, advocates, investigators, clinical research staff, and collaborating research partners 4
Slide 5: We have built a sustainable, high velocity engine to deliver medicines
We have built a sustainable, high velocity engine to deliver medicines Obtained Approval for 3 Medicines > 2,000 > 30 trials 3 fully + 1 Positive patients in > 30 countries enrolled Phase 3 Result trials > 500 sites pivotal trials > 70 > 35 19 < $10M and papers academic INDs created < 3 yrs to IND p
Slide 6: Two observations stemming from BBP-418
Two observations stemming from BBP-418 Small molecules can • Can provide more clinical efficacy than newer technologies provide an optimal • Often have a more favorable safety profile therapeutic profile • More cost effective Delivering meaningful clinical improvement, • BBP-418 demonstrated improve
Slide 7: Introduction
Introduction Christine Siu Chief Executive Officer ML Bio Solutions, a BridgeBio company BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 7
Slide 8: With BBP-418, we aim to provide a critically needed, first-to-market therapy
With BBP-418, we aim to provide a critically needed, first-to-market therapy for individuals living with LGMD2I/R9 “ It's scary to think [about] the future, and the hope of there being something that just allows us to live our life without as much grief and loss is exciting for all of us. - Julie ”
Slide 9: Highly statistically significant results on primary and all key secondary endpoints
Highly statistically significant results on primary and all key secondary endpoints, including biomarker and clinical measures at 12 months Primary endpoint (3 months) p-value Change from baseline in glycosylated αDG, % of control p<0.0001 Key secondary endpoints (12 months) p-value Change from base
Slide 10: Unprecedented and consistent improvement across primary and all key secondary efficacy endpoints
Unprecedented and consistent improvement across primary and all key secondary efficacy endpoints combined with well-tolerated safety profile Ph. 3 FORTIFY interim analysis Type Endpoint Upside case target Outcome observed • Statistically significant increase vs. placebo Highly statistically signif
Slide 11: FORTIFY Phase 3 interim analysis topline results
FORTIFY Phase 3 Douglas Sproule, MD, MSc interim analysis Chief Medical Officer topline results ML Bio Solutions, a BridgeBio company BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 11
Slide 12: Thank you
Thank you to patients and families, advocates, physicians, clinical research staff, and collaborating research partners. We appreciate the LGMD2I/R9 community for all you do on behalf of LGMD patients. 12
Slide 13: FORTIFY is an ongoing randomized, placebo-controlled Phase 3 study with a planned interim analysis
FORTIFY is an ongoing randomized, placebo-controlled Phase 3 study with a planned interim analysis BBP-418 (N=74) BBP-418 (N~74) Screening Interim Analysis • Genetically Randomization (N=72) Open Label confirmed, 2:1 (N=112) Extension symptomatic Focus of LGMD2I/R9 today • 12-60 years of age Placebo
Slide 14: Glycosylated αDG overview & results
Glycosylated αDG Uma Sinha, PhD overview & results Chief Scientific Officer BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 14
Slide 15: LGMD2I/R9 is caused by mutations in FKRP that result in reduced glycosylation of alpha-dystroglycan
LGMD2I/R9 is caused by mutations in FKRP that result in reduced glycosylation of alpha-dystroglycan (αDG), leading to progressive muscle damage Molecular pathogenesis of LGMD2I/R9 • In healthy muscle cells, alpha-dystroglycan (αDG) plays an important role in linking the muscle cell membrane (sarcole
Slide 16: Proprietary, validated Western Blot assay to measure glycosylated αDG
We have developed a proprietary, validated Western Blot assay to accurately and reliably measure glycosylated αDG directly in skeletal muscle tissue Validated Western Blot evaluates change from baseline in glycosylated alpha-dystroglycan (αDG)1,2 untreated + 3 months + 6 months LGMD2I/R9 patient BBP
Slide 17: Statistically significant increase in glycosylated αDG sustained at 12 months
Observed statistically significant increase (+17% of control) from baseline in glycosylated αDG for BBP-418 treated, which was sustained at 12 months Change from baseline in glycosylated αDG (+/- 99% CI) 40 Glycosylated αDG (% of control) BBP-418 Placebo p<0.0001 LS Mean Estimate CFB in 30 p<0.0001
Slide 18: FORTIFY Phase 3 interim analysis topline results (Continued)
FORTIFY Phase 3 interim analysis Douglas Sproule, MD, MSc topline results Chief Medical Officer (Continued) ML Bio Solutions, a BridgeBio company BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 18
Slide 19: Reduction in serum CK of 82% from baseline at 12 months
BBP-418 treated patients experienced a large, statistically significant reduction in serum CK of 82% from baseline at 12 months Reduction in muscle damage Change from baseline in serum creatine kinase (U/L) 400 186 0 -400 -800 -1,869 -1,200 -1,600 -2,000 Placebo BBP-418 (n=22) p<0.0001 (n=46) Least-
Slide 20: Difference of 0.27 m/s between BBP-418 and placebo in 100MTT
Difference of 0.27 m/s observed between BBP-418 and placebo arms in 100MTT, translating to difference of ~14 seconds faster Improved ambulatory function Change from baseline in 100-meter timed test (m/s) 0.15 0.10 0.14 0.05 0.00 -0.05 -0.12 -0.10 -0.15 Placebo BBP-418 (n=20) p<0.0001 (n=40) Least-Sq
Slide 21: ~3% increase in predicted volume from baseline FVC
BBP-418 treated registered ~3% increase in predicted volume from baseline FVC, resulting in a difference of ~5% predicted volume vs. placebo Improved pulmonary function Change from baseline in forced vital capacity, sitting position (% predicted) 3 2 3.0% 1 ~2% decline is consistent with annual rate
Slide 22: More than stabilization: clinically meaningful improvements across clinical endpoints
More than stabilization: BBP-418 treated individuals experienced significant, clinically meaningful improvements across clinical endpoints at 12 months Improved ambulatory function Improved pulmonary function CFB in 100MTT (m/s) CFB in FVC (% predicted) 0.15 3 0.10 2 0.14 3.0% 0.05 1 0.00 0 -0.05 -0
Slide 23: Continued highly favorable safety profile of BBP-418
Continued highly favorable safety profile of BBP-418 • No new or unexpected safety findings have been observed; results consistent with Ph. 2 • Discontinuation rate was low overall and higher in the placebo group • No treatment-related serious TEAEs were observed Interim analysis continues to suppor
Slide 24: Next steps
Next steps Topline results from Phase 3 FORTIFY study interim analysis October 2025 Engage FDA prior to NDA submission Late 2025 / Early 2026 Present Phase 3 FORTIFY study interim analysis results MDA Clinical & Scientific Conference March 2026 File New Drug Application (NDA) with FDA 1H 2026 U.S.
Slide 25: Commercial launch plans
Commercial Matt Outten launch plans Chief Commercial Officer BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 25
Slide 26: We will leverage our proven commercial infrastructure to successfully launch BBP-418
We will leverage our proven commercial infrastructure to successfully launch BBP-418 Built on the foundation of Attruby’s commercial success and tailored to the unique LGMD2I/R9 market opportunity Proven launch playbook Ensure broad access Established commercial infrastructure Enabling faster and mo
Slide 27: Q&A session
Q&A session BBP-418 is an investigational therapy and has not been approved for use by any regulatory agency. 27