MariTide Phase 2: Amgen reports up to 20% weight loss at one year
Decision brief
Answer first · skim in under a minute
Amgen’s MariTide Phase 2 obesity study reported up to ~20% average weight loss at one year in participants without type 2 diabetes and up to ~17% in those with type 2 diabetes. The plan below focuses only on the trial facts, the placebo comparisons, and the clinical-trial readouts already supported by source material.
Amgen’s MariTide Phase 2 obesity program reported up to roughly 20% average weight loss at one year without type 2 diabetes, and MariTide Phase 3 studies are now recruiting across sleep apnea, cardiovascular disease, and heart failure. The June 23, 2025 readout also covered participants with type 2 diabetes and cardiometabolic secondary measures.
Contents10 sections
Key Takeaways
- At 52 weeks, MariTide showed up to ~20% average weight loss without T2D (placebo 2.6%) and up to ~17% with T2D (placebo 1.4%), per Amgen’s efficacy estimand.
- Weight loss had not plateaued by week 52; HbA1c fell by up to 2.2% in people with obesity and T2D.
- Phase 2 Part 1 enrolled 592 adults; results were presented at ADA 2025 and published in NEJM.
- MariTide Phase 3 programs include OSA, ASCVD outcomes, HFpEF/HFmrEF, and a GLP-1 switch study (MARITIME-SWITCH).
What did MariTide show at 52 weeks?
In Part 1 of the Phase 2 study, once-monthly or less frequent maridebart cafraglutide produced substantial average weight loss versus placebo in people living with obesity, with or without type 2 diabetes. Amgen reported the efficacy-estimand figures above and said weight loss had not plateaued by 52 weeks.
Cardiometabolic measures also improved in pre-specified analyses, including waist circumference, blood pressure, hs-CRP, and selected lipids. In the T2D cohort, Amgen highlighted a sustained HbA1c reduction of up to 2.2%. Primary disclosure is the June 23, 2025 PR Newswire release.
How does MariTide Phase 3 expand the program?
Amgen has moved MariTide beyond chronic weight management into comorbidity outcomes. A recruiting Phase 3 trial compares maridebart cafraglutide with placebo in adults with obstructive sleep apnea not on PAP therapy (NCT07226765). A parallel OSA study enrolls participants already on PAP (NCT07225686).
Cardiovascular and heart-failure Phase 3 studies are also active: ASCVD outcomes in overweight or obesity (NCT07037433) and HFpEF or mildly reduced ejection fraction with obesity (NCT07037459). MARITIME-SWITCH (NCT07575399) evaluates switching from GLP-1 receptor agonists to MariTide.
Phase 2 design and publication status
Amgen described the Phase 2 study (NCT05669599) as enrolling 592 adults into cohorts with and without type 2 diabetes, testing several monthly or less frequent dose regimens. Full results were presented at the American Diabetes Association 85th Scientific Sessions and simultaneously published in The New England Journal of Medicine.
- Primary endpoint focus: percent body-weight change at about one year versus placebo
- Molecule: maridebart cafraglutide (formerly AMG 133), GLP-1 agonist / GIP antagonist peptide-antibody conjugate
- Peer-reviewed summary indexed on PubMed 40549887
Cardiometabolic signals beyond the scale
Beyond weight loss, Amgen emphasized improvements across waist circumference, blood pressure, hs-CRP, and lipids. Those secondary signals matter for MariTide Phase 3 positioning against weekly incretin competitors, because payers and regulators increasingly ask whether obesity agents also move cardiovascular risk markers. Independent outcome trials will still be required to prove hard CV or HF benefit.
Tolerability and dose-escalation findings
Alongside efficacy, Amgen presented Phase 1 pharmacokinetics low-dose initiation data arguing that lower starting doses with escalation improved gastrointestinal tolerability without compromising efficacy. That claim is company-reported from the ADA symposium package and should be read as supportive pharmacology, not as a completed Phase 3 safety database.
What remains unproven
Phase 2 does not establish MariTide superiority to weekly GLP-1 or dual-agonist standards of care, nor does it prove cardiovascular outcome benefit. Pricing is undisclosed. FDA approval has not been granted. Until MariTide Phase 3 weight-management and comorbidity trials read out, the 20% and 17% figures remain mid-stage estimates under Amgen’s efficacy estimand, not labeled claims.
Related NovaPharma coverage
- MariTide Phase 2 obesity data show up to 20% weight loss at one year
- Novo Nordisk Wegovy supply stabilizes as FDA shortage ends
- Eli Lilly pipeline and deals: GLP-1, vaccines, and 2026 outlook
Frequently Asked Questions
What weight loss did MariTide show in Phase 2?
Per Amgen’s efficacy estimand at 52 weeks, MariTide achieved up to about 20% average weight loss without type 2 diabetes versus 2.6% on placebo, and up to about 17% with type 2 diabetes versus 1.4% on placebo.
What is MariTide’s dosing schedule?
MariTide (maridebart cafraglutide) is a peptide-antibody conjugate given subcutaneously monthly or less frequently, positioned by Amgen as a monthly or less frequent obesity treatment.
Which MariTide Phase 3 trials are recruiting?
ClinicalTrials.gov lists recruiting Phase 3 studies in obstructive sleep apnea with and without PAP therapy (NCT07226765, NCT07225686), atherosclerotic cardiovascular disease outcomes (NCT07037433), and heart failure with preserved or mildly reduced ejection fraction plus obesity (NCT07037459).
Primary Sources
Regulatory catalyst tracker
Track PDUFA dates, approval milestones, and label updates for MariTide.
Unlock full calendar →Amgen pipeline snapshot
One-screen view of active programs, phases, and recent catalysts from public sources.
Entity graph
Continue Exploring
Open the drugs, companies, and topics behind this story.
This article follows our editorial standards. Report a correction via editorial contact.
Deeper reading
Industry reports & whitepapers
- Ensuring Compatibility for GLP-1-based Drugs — The rise of GLP-1 agonists like Semaglutide demands innovative ready-to-use cartridges to enhance de…