Altimmune Designs 1,800-Patient Phase 3 Trial for Pemvidutide with 1.8mg Focus
Altimmune’s Phase 2 IMPACT program for pemvidutide in MASH showed improvements in liver stiffness, ELF score and liver fat content at a 1.8 mg dose with anti-fibrotic evidence at week 48 and low discontinuation rates. The pivotal Phase 3 trial will enroll approximately 1,800 F2/F3 MASH patients in biopsy and NIT cohorts, titrating from 1.2 to 1.8 mg or 2.4 mg, with 52-week endpoints supporting potential accelerated approval and five-year clinical outcomes.
1. Phase 2 IMPACT Program Data
Altimmune’s Phase 2 IMPACT program for pemvidutide in metabolic dysfunction‐associated steatohepatitis (MASH) demonstrated statistically significant improvements in non‐invasive markers including ELF score, liver stiffness and liver fat content at a 1.8 mg dose with anti‐fibrotic evidence by week 48. The 1.8 mg arm showed comparable or greater benefits than an approved MASH product, low gastrointestinal adverse events, and supported FDA Breakthrough Therapy designation for pemvidutide.
2. Pivotal Phase 3 Trial Design
The single pivotal Phase 3 study will enroll approximately 1,800 patients with F2/F3 MASH across two cohorts: 990 biopsy‐confirmed subjects randomized equally to placebo, 1.8 mg and 2.4 mg arms, plus 800 patients assessed by non‐invasive tests. Participants will start at 1.2 mg and titrate to target doses, with primary endpoints at 52 weeks for MASH resolution or fibrosis improvement, targeting accelerated approval and requiring five‐year outcomes for final clearance.
3. Financials and Additional Programs
In Q4 2025, Altimmune reported R&D expense of $18.4 million, including $12.8 million on pemvidutide development, and G&A expense of $10.5 million driven by stock compensation and payroll charges. Altimmune reiterated expectations for Q3 2026 top-line data from its Phase 2 AUD study (RECLAIM) and continues enrollment in its Phase 2 ALD study (RESTORE), with completion expected later in 2026.