Phase 2 obesity research showed substantial weight loss, while randomized MASLD/MASH trials demonstrated large liver-fat reductions and MASH-resolution signals. A global Phase 3 MASH programme began in 2026.
Regulatory status
Investigational. FDA granted Breakthrough Therapy Designation for MASH based on early clinical evidence; this is not marketing approval.
Main limitations
Marketing approval, long-term liver outcomes, definitive fibrosis benefit, cardiovascular outcomes and routine-use dosing are not established.
Safety
GI tolerability and liver-disease population safety are being characterised; longer-term and rare-event data remain limited.
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Phase 2 obesity research showed substantial weight loss, while randomized MASLD/MASH trials demonstrated large liver-fat reductions and MASH-resolution signals. A global Phase 3 MASH programme began in 2026.
What the evidence actually supports
✓Useful obesity evidence, but source quality should be labelled conference abstract.
✓Must show positive and null primary endpoints side by side.
What is not established / key limitations
×Primary obesity result is conference publication rather than full peer-reviewed journal paper in the reviewed source set.
×Fibrosis improvement without worsening MASH was 33%/36% vs 28% and not statistically significant.
GI tolerability and liver-disease population safety are being characterised; longer-term and rare-event data remain limited.
Adverse events are common but mostly mild-to-moderate in reported trials; gastrointestinal tolerability remains important. Fibrosis benefit was not statistically significant at 24 weeks in the Phase 2b IMPACT primary fibrosis endpoint.
Technical details
Mechanism / biologyBalanced GLP-1/glucagon receptor agonism aims to reduce appetite and body weight while increasing hepatic fat oxidation and improving metabolic liver disease.
Route / formulation boundaryTrial-grade once-weekly subcutaneous product; Breakthrough Therapy designation must not be presented as FDA approval.
Identity / data-quality noteSeparate obesity, MASLD and biopsy-confirmed MASH endpoints; do not treat Breakthrough Therapy as approval.
Dosing evidence statusMultiple Phase 2 human regimens verified. MOMENTUM studied 1.2, 1.8 and 2.4 mg weekly for 48 weeks; IMPACT studied 1.2 and 1.8 mg weekly without titration.
Identifiers & alternate namesALT-801
Evidence rule: WhichPeps keeps human, animal, laboratory, regulatory and product/formulation evidence distinct. Common names help people find the page; they do not change the underlying scientific identity.
