Slide 1: Altimmune Corporate Overview
Altimmune Corporate Overview March 2026 Our Mission: To Revolutionize the Standard of Care for Serious Liver Diseases
Slide 2: Forward Looking Statements
Forward Looking Statements 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 limited to, statements
Slide 3: Evolved Leadership Team to Position Company for Late-Stage Clinical Success
Evolved Leadership Team to Position Company for Late-Stage Clinical Success Jerry Durso Linda Richardson Greg Weaver Christophe President and Chief Chief Commercial Officer Chief Financial Officer Arbet-Engels, MD, PhD Executive Officer Chief Medical Officer Scot Roberts, PhD Robin E. Abrams, JD Car
Slide 4: Late-stage Biopharma Focusing on Serious Liver Diseases
Late-stage Biopharma Focusing on Serious Liver Diseases Lead candidate, Advancing Compelling AUD topline Robust patent pemvidutide: pipeline Phase 2 MASH data expected in portfolio unique, dual- programs in data; program 3Q 2026 from covering action therapy MASH, Alcohol progressing ongoing Phase 2
Slide 5: The Molecule Matters
The Molecule Matters EuPort COOH Delayed Tmax with Lower Cmax EuPort Pemvidutide (CH2)n Domain Better Tolerability Glucagon specificity GLP-1 specificity Direct impact on the liver and metabolism Direct impact on GI and CNS 5 MASH = Metabolic Dysfunction-Associated Steatohepatitis
Slide 6: Pemvidutide: Addressing Both the Cause and Consequence of Serious Liver Diseases
Pemvidutide: Addressing Both the Cause and Consequence of Serious Liver Diseases Currently available therapies often do not treat the totality of the disease, provide limited effectiveness, or have a poor tolerability profile Pemvidutide: Balanced 1:1 glucagon/GLP-1 dual receptor agonist Glucagon GL
Slide 7: Priority Programs in Serious Liver Diseases
Priority Programs in Serious Liver Diseases Phase of Development Pemvidutide Pre-clinical Phase 1 Phase 2 Phase 3 Key Catalysts • 4Q25: IMPACT Phase 2b 48w data MASH (FDA Fast Track Designation) • 4Q25: End of Phase 2 FDA (FDA Breakthrough Therapy meeting complete Designation) • 2026: Commence Phase
Slide 8: IMPACT Phase 2b MASH Trial Design
IMPACT Phase 2b MASH Trial Design Screening/Randomization Placebo (PBO) weekly Key Eligibility Criteria 1.2 mg weekly MASH (F2/F3) LFC(1) ≥ 8% BMI ≥ 27.0 kg/m2 1.8 mg weekly HbA1c ≤ 9.5% N = 212 subjects randomized 2:1:2 No dose titration Key Endpoints Primary Week 24 Week 48 MASH resolution
Slide 9: Early Effect on MASH + Tolerability Observed at 24 Weeks
Early Effect on MASH + Tolerability Observed at 24 Weeks 24 Weeks 1 2 3 Rapid and significant reductions Weight loss with Trending improvement in liver fat and markers of no evidence of plateauing of fibrosis as measured by inflammation, with early MASH at 24 weeks biopsy data resolution 4 5 + Resul
Slide 10: Topline Results Achieved Key Measures of Success at 48 Weeks
Topline Results Achieved Key Measures of Success at 48 Weeks 48 Weeks 1 2 Further improvements Established clear dose response in NITs including antifibrotic with strong 1.8 mg performance observed on activity in ELF and LSM (Fibroscan) all evaluated parameters, including additional weight loss 3 4
Slide 11: Substantial Improvements in Non-invasive Markers of Fibrosis at 48 Weeks
Substantial Improvements in Non-invasive Markers of Fibrosis at 48 Weeks, Dose Response Favors 1.8 mg ≥0.5 ELF Reduction + 30% LSM Enhanced Liver Fibrosis (ELF) Liver Stiffness Measurement (LSM) Reduction Threshold 0.50 0.0 100 -0.5 LS Mean Change from Baseline (kPa ± SE) 90 0.16 LS Mean Change from
Slide 12: Improvements in Primary Non-invasive Markers of Fibrosis from 24 to 48 Weeks
Improvements in Primary Non-invasive Markers of Fibrosis from 24 to 48 Weeks with 1.8 mg, Supporting Phase 3 Development Enhanced Liver Fibrosis (ELF) Liver Stiffness Measurement (LSM) Placebo-Adjusted Placebo-Adjusted 0 0 LS Mean Change from Baseline (kPa ± 95% CI) -1 LS Mean Change from Baseline (
Slide 13: Enhanced Liver Fibrosis (ELF) Response
Enhanced Liver Fibrosis (ELF) Response Placebo adjusted based upon published data Pemvidutide (GLP-1/GCG) Resmetirom (THR-β) Tirzepatide (GLP-1/GIP) Semaglutide (GLP-1) Efruxifermin (FGF21) Pemvidutide Phase 2b Phase 3 Phase 2 Phase 3 Phase 2b shows strong ELF response at 48 0.40 weeks Placebo-Adjus
Slide 14: LSM (Fibroscan) Response
LSM (Fibroscan) Response Placebo adjusted based upon published data Pemvidutide (GLP-1/GCG) Resmetirom (THR-β) Tirzepatide (GLP-1/GIP) Semaglutide (GLP-1) Efruxifermin (FGF21) Pemvidutide Phase 2b Phase 3 Phase 2 Phase 3 Phase 2b shows significant improvement in 2.0 LSM at 48 weeks Placebo-Adjusted
Slide 15: 1.8 mg Dose Maintained >50% Reduction in Liver Fat Over 48 Weeks
1.8 mg Dose Maintained >50% Reduction in Liver Fat Over 48 Weeks Liver Fat Content Reduction 80 Similar levels of liver fat LS Mean Relative Change from Baseline (% ± SE) 70 reduction were observed as **** 54.7 early as 24-weeks 60 **** 45.2% 50 Liver fat content is a key 40 driver of MASH and fibro
Slide 16: Significant Reductions in Alanine Aminotransferase (ALT) at 48 Weeks
Significant Reductions in Alanine Aminotransferase (ALT) at 48 Weeks Alanine Aminotransferase (ALT) ≤30 IU/L ALT Threshold 0 100 -5 ALT is a measure of hepatic 90 inflammation and disease ** LS Mean Change from Baseline (IU/L ± SE) -10 *** 80 73.7% 72.0% -15 -10.3 -17 >17 IU/L reduction is 70 Propor
Slide 17: Significant Reductions in Corrected T1 (cT1)
Significant Reductions in Corrected T1 (cT1) Reduction of ≥80 ms is associated with an improvement in histology in MASH† cT1 cT1 is a non-invasive 0 marker of hepatic LS Mean Change from Baseline (ms ± SE) inflammation -21 -50 80 ms reduction in cT1 is -80 ms associated with 2-point -100 reduction i
Slide 18: Significant and Continuing Weight Loss for 1.8 mg at 48 Weeks
Significant and Continuing Weight Loss for 1.8 mg at 48 Weeks Weight Loss Weight Loss 0 1 -1 -0.2% Weight loss has been 0 shown to be associated LS Mean Relative Change from Baseline (% ± SE) LS Mean Relative Change from Baseline (% ± SE) -2 -1 with MASH -3 -2 improvement† -4 -3 Weight loss of 7.5%
Slide 19: Safety Profile Maintained at 48 Weeks
Safety Profile Maintained at 48 Weeks Placebo 1.2 mg 1.8 mg (N=86) (N=41) (N=85) Serious AEs 5 (5.8%) 1 (2.4%) 8 (9.4%) Serious AEs related to study med 0 (0.0%) 0 (0.0%) 0 (0.0%) Severe AEs 2 (2.3%) 1 (2.4%) 8 (9.4%) Severe AEs related to study med 0 (0.0%) 0 (0.0%) 0 (0.0%) AEs of Special Interest
Slide 20: Favorable Tolerability at 48 Weeks
Favorable Tolerability at 48 Weeks Placebo 1.2 mg 1.8 mg Adverse Events (N=86) (N=41) (N=85) Nausea 15 (17.4%) 9 (22.0%) 35 (41.2%) Vomiting 2 (2.3%) 3 (7.3%) 10 (11.8%) Diarrhea 7 (8.1%) 5 (12.2%) 19 (22.4%) Constipation 10 (11.6%) 5 (12.2%) 15 (17.6%) AEs leading to treatment discontinuation 3 (3.
Slide 21: Early Occurrence of GI AEs in Phase 2b Emphasize Tolerability and Support Simple Titration
Early Occurrence of GI AEs in Phase 2b Emphasize Tolerability and Support Simple Titration Gastrointestinal Adverse Events GI tolerability of 1.2 mg dose was similar to placebo Majority of GI AEs occur in first month of dosing Data support a simple one- or two-step titration in Phase 3 to further im
Slide 22: Maintenance of HbA1c Regardless of Diabetes Status at 48 Weeks
Maintenance of HbA1c Regardless of Diabetes Status at 48 Weeks Change in HbA1c from Baseline, Placebo 1.2 mg 1.8 mg Week 48 (N=65) (N=34) (N=72) All Subjects, %, LSM (SE) 0.10 (0.10) -0.24 (0.13) 0.01 (0.09) Diabetic, %, LSM (SE) -0.02 (0.21) -0.64 (0.29) -0.12 (0.20) Non-diabetic, %, LSM (SE) 0.09
Slide 23: Phase 2 Insights Inform Optimal Phase 3 Design
Phase 2 Insights Inform Optimal Phase 3 Design Key Phase 2 Takeaways Phase 3 Implications Rapid histological effects with MASH resolution at Primary endpoint on biopsy at 52 weeks for 1.8 week 24; antifibrotic and weight loss effects continue mg and 2.4 mg dose with potential upside on to improve th
Slide 24: MASH Phase 3 Trial Readiness
MASH Phase 3 Trial Readiness Finalizing protocol and key operational elements Screening/Randomization Cohort 1 Week 52 (subpart H) confirmed F2/F3 Placebo (PBO) weekly Accelerated approval: Biopsy * 1.2 mg Follow Followonon toto Week 52 (subpart H) efficacy MASH 4 weeks 1.8 1.2 – 2.8 mgmg outcomes
Slide 25: MASH Treatment Landscape
MASH Treatment Landscape Pemvidutide Target Profile Early Market Opportunities HCPs see high unmet need for new options for patients who discontinue GLP-1 therapy Early, direct-acting liver effects and due to tolerability issues or lack of efficacy significant metabolic improvements Pemvidutide’s po
Slide 26: Exploring Pemvidutide's Potential in Other Progressive Liver Diseases
Exploring Pemvidutide’s Potential in Other Progressive Liver Diseases Alcohol-Associated Alcohol Use Disorder (AUD) 5+/day Liver Disease (ALD) • Impaired ability to stop or control the harmful • Progression of AUD, with serious liver health consumption of alcohol consequences • 12 million adults in
Slide 27: Growing Body of Evidence Support Development of Pemvidutide for AUD
Growing Body of Evidence Support Development of Pemvidutide for AUD Pre-clinical studies Clinical profile and Other randomized Additional Large players show up to 82% data from clinical trial real-word data in biopharma reduction in IMPACT Phase 2 demonstrate low- demonstrates industry alcohol intak
Slide 28: Potential Differentiation in the AUD and ALD Marketplace
Potential Differentiation in the AUD and ALD Marketplace Reduction in Alcohol Targeted Weight Consumption / Heavy Liver-Directed Loss Drinking Days Mechanism Pemvidutide Disulfiram Acamprosate Naltrexone GLP-1s No head-to-head studies of pemvidutide to other AUD or ALD products or product candidates
Slide 29: RECLAIM Phase 2 AUD Trial Design
RECLAIM Phase 2 AUD Trial Design N = 100 subjects randomized 1:1 Screening/Randomization Placebo (PBO) 1.2 mg Key Eligibility Criteria weekly 1.8 mg weekly 2.4 mg Moderate to severe AUD 4 Weeks 4 Weeks At least 28 drinks per week Week 24 if male; 21 drinks per week if female BMI ≥ 25 kg/m2 End
Slide 30: RESTORE Phase 2 ALD Trial Design
RESTORE Phase 2 ALD Trial Design N = 100 subjects randomized 1:1 Screening/Randomization Placebo (PBO) 1.2 mg Key Eligibility Criteria weekly 1.8 mg weekly 2.4 mg History of heavy alcohol 4 Weeks 4 Weeks use with continued Week 24 Week 48 consumption Liver stiffness of 10.0-18.5 kPa Primary &
Slide 31: Strong Clinical Execution and Future Catalysts
Strong Clinical Execution and Future Catalysts 2025 2026 2027 • MASH: IMPACT Phase 2b 24- and • MASH: FDA Breakthrough • MASH: Phase 3 trial 48-Week data Therapy Designation Granted execution ongoing • MASH: End-of-Phase 2 meeting • MASH: Phase 3 trial initiation • AUD: Phase 3 opportunity • AUD: RE
Slide 32: Thank you
altimmune