Amgen opens the MARITIME-2 long-term extension to enrollment

Amgen's MARITIME-2-EXTENSION, a Phase 3 long-term extension study of its experimental obesity drug MariTide, has switched from "not yet recruiting" to "recruiting." The study is designed to test whether weight loss achieved in the main trial can be maintained when people stay on MariTide given once a month or once every eight weeks.

MARITIME-2-EXTENSION enrolls adults with obesity, or overweight, who also have type 2 diabetes. A parallel extension tied to MARITIME-1 covers participants without diabetes and goes further on spacing: it evaluates monthly, every-eight-week and quarterly maintenance dosing.

That design detail is the point. MariTide is given by injection, and Amgen has framed the drug's main selling point as fewer shots per year than the weekly injectables now on the market. Claims of roughly four to six doses a year only hold up if a dose given every eight weeks — or every three months — keeps weight off after people finish the initial treatment period. Extension studies are where that gets measured.

The status flip matters more than it sounds. A change from "not yet recruiting" to "recruiting" means sites are open and screening patients, rather than sitting in setup. It is also the kind of update that is easy to miss: the federal trial registry overwrites a record when a sponsor edits it and keeps no public log of the prior value, so a status change, a moved reporting date or a resized enrollment target is invisible the day after it happens unless someone captured the earlier version ^[1].

Several specifics have not been disclosed, including how many participants each extension will enroll, how long the maintenance period runs, how much weight participants must have lost to enter, and when results are expected. Whether the extensions include a group that stops MariTide entirely — the comparison that would show how much of the weight comes back without the drug — has not been reported.

Amgen has been pushing its later-stage pipeline in public. On Aug. 4, 2026, the company reported second-quarter revenue up 10% to $10.1 billion, and chief executive Robert A. Bradway said Amgen was working to "advance the next wave of pipeline molecules through Phase 3" ^[2].

Why it matters for patients

For people on GLP-1 drugs today, the most common practical complaints are the weekly injection routine, side effects and cost. A monthly or quarterly option would change the routine part. It would not automatically change the other two.

The extension studies also speak to a question many patients ask: what happens after the first year. Studies of currently approved GLP-1 medicines have generally shown that weight tends to return when treatment stops, which is why maintenance dosing is a commercial and clinical priority. MARITIME-1-EXTENSION and MARITIME-2-EXTENSION are built to answer whether a stretched-out schedule is enough to hold the line — and, separately, whether side effects are more tolerable or less tolerable when a larger amount of drug is delivered less often. Longer gaps between doses can mean bigger swings in drug levels, and how that affects nausea and vomiting rates in these extensions has not yet been reported.

MariTide is not approved anywhere. It cannot be prescribed, and nothing about these studies changes what is available at a pharmacy now.

What happens next

Recruiting status means enrollment is underway, but Amgen has not published a target date for completing enrollment or for reporting maintenance results from either extension. Because the two extensions split by diabetes status, results may arrive separately for people with and without type 2 diabetes.

Any US filing would follow the main MARITIME Phase 3 trials, not the extensions, though long-term maintenance data would likely factor into labeling discussions about dosing intervals. No regulatory submission date for MariTide has been announced.