Amgen's MariTide readouts now sit outside the 2026 window

Amgen's obesity drug candidate MariTide, a peptide-antibody combination that activates the GLP-1 receptor while blocking the GIP receptor, now has its key Phase 3 results pushed to early 2027 instead of sometime in 2026 ^[1]. The drug is being tested in nine global Phase 3 studies covering obesity, obstructive sleep apnea, cardiovascular disease and heart failure, with the two main obesity trials, called MARITIME-1 and MARITIME-2, both carrying a primary completion date of January 21, 2027 ^[1].

In earlier Phase 2 testing, people taking MariTide lost roughly 20 percent of their body weight on average at 52 weeks when measured under the strictest scientific standard, which counts only people who stayed on the drug as directed, and the weight loss curve had not leveled off by that point ^[1]. When the analysis instead counted everyone who started treatment, including people who quit early, average weight loss was lower, between 12.3 and 16.2 percent ^[1]. That gap between the two numbers points to a real-world problem: some people stopped taking the drug before finishing the study, often because of vomiting and other stomach-related side effects ^[1]. In response, Amgen slowed how quickly patients move up to higher doses in the Phase 3 studies, a change meant to make the drug easier to tolerate ^[1].

One of the ongoing Phase 3 studies is enrolling people who are already taking weekly tirzepatide (sold as Mounjaro or Zepbound) or weekly semaglutide (sold as Ozempic or Wegovy) and switching them onto MariTide instead ^[1]. MariTide is designed to be dosed monthly rather than weekly, which Amgen is positioning as a convenience advantage over the currently approved drugs ^[1]. Amgen's stock market value sits at roughly $191.7 billion, and MariTide is now the company's only clinical-stage obesity candidate after Amgen discontinued an earlier, undisclosed early-stage obesity drug in August 2026 ^[1].

Why it matters for patients

For people currently deciding between GLP-1 drugs, MariTide is not an option yet and won't be for some time. The delay to early 2027 means there is no near-term new choice on the market from Amgen, and anyone hoping for a monthly injectable alternative to weekly tirzepatide or semaglutide will need to wait for these trial results and, after that, for regulatory review ^[1].

The tolerability data so far is a mixed signal. Roughly 20 percent average weight loss in the strictest analysis is competitive with the best available treatments, but the meaningfully lower numbers in the more real-world analysis, combined with reports of high discontinuation and vomiting, suggest that some patients may struggle to stay on the drug at its studied doses ^[1]. Amgen's decision to slow dose increases in Phase 3 is a direct response to that problem, and whether the change actually improves how many people can stick with treatment is something the new trials are designed to answer ^[1].

The switch study, which moves patients off weekly tirzepatide or semaglutide onto MariTide, will offer some of the first controlled data on what happens when someone changes GLP-1 drugs rather than starting one for the first time, which is a common real-world scenario as more people cycle through different treatments ^[1].

What happens next

The primary completion date for both MARITIME-1 and MARITIME-2 is listed as January 21, 2027, with Amgen guiding to an early 2027 readout for MARITIME-1 specifically ^[1]. Until those results are public, the drug's tolerability profile, its real-world effectiveness, and its regulatory timeline all remain open questions.