Slide 1: IMPACT Phase 2b MASH Trial - Topline Results
IMPACT Phase 2b MASH Trial - Topline Results Pemvidutide: Designed to be the Treatment of Choice for Liver and Cardiometabolic Diseases J u n e 2 6 , 2 0 2 5 Company Confidential
Slide 2: Forward-looking statements
Forward-looking statements Safe-Harbor Statement This presentation has been prepared by Altimmune, Inc. ("we," "us," "our," "Altimmune" or the "Company") and includes certain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not l
Slide 3: IMPACT Phase 2b MASH Trial design
1.2 mg weekly* 1.8 mg weekly* Placebo weekly Week 48 NITs Weight Loss Week 24 Liver Biopsy NITs Weight Loss Screening/Randomization IMPACT Phase 2b MASH Trial Key Eligibility Criteria • MASH (F2/F3) • LFC† ≥ 8% • BMI ≥ 27.0 kg/m2 † liver fat content † † MASH Resolution w/o worsening of fibrosis or F
Slide 4: Study Disposition
Study Disposition High Study Completion Rates with Minimal AE Discontinuations Randomized & Dosed (n = 212) Placebo (n = 85) 1.2mg pemvidutide (n = 42) 1.8mg pemvidutide (n = 85) Completed 24 Wks Treatment (n = 76) Completed 24 Wks Treatment (n = 39) Completed 24 Wks Treatment (n = 78) Biopsied at W
Slide 5: IMPACT Baseline Demographics and Disease Characteristics
IMPACT Baseline Demographics and Disease Characteristics Characteristic Placebo (n = 85) 1.2 mg (n = 42) 1.8 mg (n = 85) Age - years 52.8 (11.8) 54.4 (13.9) 53.4 (12.4) Female sex - n (%) 47 (55.3) 26 (61.9) 50 (58.8) Body weight - kg 109.1 (27.5) 112.0 (27.3) 107.7 (21.3) BMI - kg/m2 38.0 (7
Slide 6: Two Methods of Biopsy Reading Employed
Two Methods of Biopsy Reading Employed Pathologist reading • Biopsies independently scored by three pathologists using the mode method • Pathologists blinded to subject, treatment, and timepoint (sequence of sampling) Supplemental AI-based reading • Blindly scored biopsies without knowledge of treat
Slide 7: First Incretin to Demonstrate Statistically Significant MASH Resolution at 24 Weeks
First Incretin to Demonstrate Statistically Significant MASH Resolution at 24 Weeks **** p < 0.0001 vs. placebo (Chi-Square Test) Placebo (n=71) 1.2mg (n=38) 1.8mg (n=79) Completer Analysis 23.2% 66.6% p < 0.0001 56.0% p < 0.0001 Placebo (n=85) 1.2mg (n=42) 1.8mg (n=85) Multiple Imputations Analysis
Slide 8: Pemvidutide: Potential for Class Leading MASH Resolution
Response achieved at 24 weeks better than or comparable to other therapies, including those assessed at later timepoints Pemvidutide: Potential for Class Leading MASH Resolution * Pegozafermin data generated with multiple imputations; calculated efimosfermin; See slide 22 for full citations * No hea
Slide 9: Pemvidutide: Fibrosis Improvement at 24 Weeks
Pemvidutide: Fibrosis Improvement at 24 Weeks NS vs. placebo (Chi-Square Test) Placebo (n=71) 1.2mg (n=37*) 1.8mg (n=79) Completer Analysis 30.9% 35.6% 37.0% Placebo (n=85) 1.2mg (n=42) 1.8mg (n=85) Multiple Imputations Analysis 26.8% 34.7% 36.8% * 1 biopsy was interpretable for MASH resolution but
Slide 10: Fibrosis Improvement with Pemvidutide
Fibrosis Improvement with Pemvidutide * * Pegozafermin data generated with multiple imputations; calculated efimosfermin; See slide 22 for full citations No head-to-head studies of pemvidutide to other MASH products or product candidates have been conducted; the data regarding other MASH products an
Slide 11: Significant Reductions in Fibrosis by AI-Based Supplemental Analysis
Significant Reductions in Fibrosis by AI-Based Supplemental Analysis † Changes corrected for reductions in liver fat * p < 0.05 | *** p < 0.001 vs. placebo (CMH) † Analyses employing Liver Explore (Path AI) to evaluate the proportions of liver involved with pathological fibrosis 11
Slide 12: Significant Changes in Non-invasive Tests of Fibrosis at 24 Weeks
Significant Changes in Non-invasive Tests of Fibrosis at 24 Weeks * p < 0.05 | ** p < 0.005 | *** p < 0.001 vs. placebo (ANCOVA) -1.0 -0.5 0.0 0.5 ELF LS Mean Absolute Reduction from Baseline (± SE) placebo N=73 1.2 mg N=40 1.8 mg N=76 pemvidutide *** *** 0.03 -0.6 -0.5 -6 -5 -4 -3 -2 -1 0 -2.0 -3.3
Slide 13: Composite Endpoint of MASH Resolution and Fibrosis Improvement at 24 Weeks
Composite Endpoint of MASH Resolution and Fibrosis Improvement at 24 Weeks Chi-Square Test Placebo effect reduced with more stringent endpoint of MASH resolution and fibrosis improvement 13
Slide 14: Pemvidutide Reduced Liver Fat Content by up to 62.8%
Pemvidutide Reduced Liver Fat Content by up to 62.8% *** p < 0.001 vs. placebo (ANCOVA) 0 10 20 30 40 50 60 70 80 62.8% 58.0% 16.2% Liver Fat Content LS Mean Relative Reduction from Baseline (% ± SE) placebo N=75 1.2 mg N=40 1.8 mg N=79 pemvidutide *** *** ***p < 0.001 | **** p < 0.0001 vs. placebo
Slide 15: Significant Reductions in Alanine Aminotransferase (ALT)
Significant Reductions in Alanine Aminotransferase (ALT) Demonstrated Meaningful Liver Effects *** p < 0.001 vs. placebo (MMRM) -50 -40 -30 -20 -10 0 -34.4 -34.6 -10.0 Alanine Aminotransferase (ALT) ITT Analysis LS Mean Absolute Reduction from Baseline (IU/L ± SE) placebo N=85 1.2 mg N=42 1.8 mg N=8
Slide 16: Significant Weight Loss at 24 Weeks
Significant Weight Loss at 24 weeks Weight loss has been shown to be a critical element in MASH therapy1 Weight loss continuing at week 24 with no plateauing Opportunity to achieve greater weight loss with 2.4 mg dose in Phase 3 1. Vilar-Gomez E, et al. Weight Loss Through Lifestyle Modification Sig
Slide 17: Potentially Class Leading Tolerability without Dose Titration
Potentially Class Leading Tolerability without Dose Titration Placebo (n = 85) 1.2 mg (n = 42) 1.8 mg (n = 85) Serious AEs 3 (3.5%) 1 (2.4%) 3 (3.5%) Serious AEs related to study med 0 (0.0%) 0 (0.0%) 0 (0.0%) Severe AEs 2 (2.4%) 1 (2.4%) 4 (4.7%) AEs leading to treatment discontinuation 2 (2.4%) 0
Slide 18: Favorable GI Tolerability
Favorable GI Tolerability Adverse Events Placebo (n = 85) 1.2 mg (n = 42) 1.8 mg (n = 85) Nausea 12 (14.1%) 9 (21.4%) 35 (41.2%) Vomiting 2 (2.4%) 2 (4.8%) 7 (8.2%) Diarrhea 7 (8.2%) 4 (9.5%) 18 (21.2%) Constipation 8 (9.4%) 5 (11.9%) 11 (12.9%) Majority of AEs were mild in severity 18
Slide 19: Maintenance of HbA1c Regardless of Diabetes Status
Maintenance of HbA1c Regardless of Diabetes Status Change in HbA1c from Baseline, Week 24 Placebo (n = 85) 1.2 mg (n = 42) 1.8 mg (n = 85) All Subjects, %, LSM (SE) 0.00 (0.19) -0.09 (0.21) -0.12 (0.18) Diabetic, %, LSM (SE) 0.23 (0.35) 0.05 (0.42) -0.03 (0.36) Non-diabetic, %, LSM (SE) -0.02 (0.10)
Slide 20: Blood Pressure Reduction without Changes in Heart Rate
Blood Pressure Reduction without Changes in Heart Rate Change from Baseline, Week 24 Placebo (n = 85) 1.2 mg (n = 42) 1.8 mg (n = 85) Systolic Blood Pressure mmHg, LSM (SE) -1.1 (1.9) -6.6 (2.2)** -5.9 (1. 9)** Diastolic Blood Pressure mmHg, LSM (SE) -1.3 (1.2) -2.4 (1.4) -2.8 (1.1) Heart Rate bpm,
Slide 21: Pemvidutide IMPACT Phase 2b MASH Trial Summary
Pemvidutide IMPACT Phase 2b MASH Trial Summary First Product Candidate to Demonstrate Significant MASH Effects and Weight Loss at 24 Weeks • Trial met its primary endpoint with statistically significant and potentially class leading MASH resolution without worsening of fibrosis of up to 59.1% at 24
Slide 22: References
References • MASH Resolution w/o Worsening of Fibrosis o Efruxifermin: Harrison et al. Lancet 2023 (Fig 2B). ITT analysis o Pegozafermin: Loomba et al. NEJM2023 (Fig. 1B). Multiple imputations o Efimosfermin: 11/2024 Phase 2 Results Deck (calculated based on completer data; Pbo N=41, 300mg N=43). Ca
Slide 23: Thank you
Thank you 23