Amgen's Monthly MariTide Demonstrates Up to 20% Weight Loss, Advancing to Phase 3 MARITIME Program
Amgen Inc. (NASDAQ: AMGN) has presented full Phase 2 clinical data for its highly anticipated obesity candidate, MariTide (maridebart cafraglutide, formerly AMG 133), and announced the initiation of its comprehensive Phase 3 clinical program, named MARITIME.
MariTide is a first-in-class peptide-antibody conjugate with a dual mechanism of action, acting as a GLP-1 receptor agonist and a gastric inhibitory polypeptide receptor (GIPR) antagonist. Its long half-life allows for once-monthly or even less frequent subcutaneous administration, presenting a highly differentiated profile compared to existing once-weekly injectables like Ozempic/Wegovy and Mounjaro/Zepbound.
Key Phase 2 Clinical Findings
- Efficacy in Obesity (without Type 2 Diabetes): At 52 weeks, MariTide achieved up to ~20% average weight loss (efficacy estimand) compared with 2.6% for placebo. Crucially, weight loss had not reached a plateau by Week 52, indicating the potential for further weight reduction with longer treatment.
- Efficacy in Obesity with Type 2 Diabetes: MariTide achieved up to ~17% average weight loss (efficacy estimand) compared with 1.4% for placebo, accompanied by a robust reduction in HbA1c of up to 2.2%.
- Cardiometabolic Improvements: Treatment led to significant improvements across waist circumference, blood pressure, high-sensitivity C-reactive protein (hs-CRP), and lipid profiles.
- Tolerability and Titration: The most common adverse events were mild-to-moderate gastrointestinal symptoms. Amgen's Phase 1 Pharmacokinetics Low Dose Initiation (PK-LDI) study demonstrated that starting with lower doses (starting at 21 mg, followed by 35 mg, and then 70 mg) significantly improved GI tolerability, with zero discontinuations due to GI events in the low-dose initiation groups.
Phase 3 MARITIME Expansion
Amgen has initiated its 72-week Phase 3 MARITIME program in chronic weight management using these optimized, low-dose escalation titration schedules. Additionally, Amgen plans to launch Phase 3 cardiovascular outcome trials (for ASCVD and heart failure) and obstructive sleep apnea trials using MariTide.
Financial Context
Amgen's financial profile remains robust as it funds this expensive late-stage program. According to Amgen's Q1 2026 financial results, the company reported $8.62 billion in quarterly revenue (+5.8% YoY) and an EPS of $5.15, beating analyst expectations of $4.77. The company holds a market capitalization of $181.77 billion and has $12.04 billion in cash, providing ample liquidity to support the global MARITIME trials.