Three Drugmakers Advance Obesity Pipelines with New Mechanisms and Clinical Plans

Amgen Inc. (AMGN) is preparing a new Phase 2b trial called "Phase 2b Randomized, Double-blind, Placebo-controlled Trial to Evaluate the Efficacy, Safety and Tolerability of Maridebart Cafraglutide in Adult Participants Living With Elevated Liver Fat and Obesity or Overweight." The study aims to see if its drug can lower liver fat and body weight in adults with obesity or overweight.

The trial will test maridebart cafraglutide, also known as AMG 133, given as a shot under the skin. The goal is to see whether this treatment, used with diet and exercise, can deliver better liver fat reduction and weight loss than a dummy shot. The record shows the study was first submitted on February 6, 2026. The latest update was filed on February 26, 2026, suggesting planning and setup are active even though recruitment has not yet started.

Celltrion unveiled a dual-track obesity drug strategy featuring a quad-action injectable and an oral pill. The injectable candidate, CT-G32, targets four biological pathways simultaneously, moving beyond the dual- and triple-action GLP-1-based therapies that currently dominate the market. Celltrion said the drug aims to minimize side effects such as muscle loss and efficacy variation among patients while enhancing appetite suppression and weight reduction. The company plans to file an investigational new drug application in the first half of 2027.

The oral candidate acts on multiple targets including GLP-1 receptors, distinguishing it from rival oral treatments that rely on a single mechanism. Celltrion said the pill is expected to broaden patient access by offering easier storage and administration compared to injectables, with an IND filing targeted for the second half of 2028. The South Korean drugmaker said the two treatments are designed to complement each other across different stages of obesity care — the injectable for patients requiring aggressive early weight loss, and the oral drug for those seeking long-term maintenance or alternatives to injections.

According to GlobalData, the worldwide obesity drug market is expected to grow to $173.5 billion by 2031, as the worldwide adult overweight rate has surged past 40 percent from about 25 percent in the 1990s.

Palatin Technologies plans to move two obesity-targeting drugs — experimental therapies designed to activate the melanocortin-4 receptor (MC4R) protein, which is involved in appetite and energy balance — into clinical testing in people with Prader-Willi syndrome (PWS) this year. Planned trials will also test the company's candidates in people with hypothalamic obesity, a disorder that, like PWS, is marked by insatiable hunger.

PL7737 is an experimental oral therapy that's now completing required preclinical studies to confirm its safety before it can be tested in first-in-human studies. Data from animal studies to date show that PL7737 is well absorbed when taken by mouth and leads to significant weight loss. The company plans to submit an investigational new drug application (IND) to the U.S. Food and Drug Administration, seeking clearance for a Phase 1 trial to test increasing single and multiple doses of PL7737 in people with PWS or hypothalamic obesity. The company expects to launch that study in the first half of this year.

In parallel, Palatin plans to file an IND for clearance of a similarly-designed Phase 1 trial to test a yet-to-be-selected next-generation peptide MC4R agonist that will be administered via subcutaneous, or under-the-skin, injections once weekly. Both the regulatory submission and the trial's start are expected in the second half of the year.

Palatin is aiming to develop MC4R agonists that are tolerated better by patients and have the potential to cause fewer gastrointestinal side effects and skin hyperpigmentation — a known side effect of MC4R agonists. Targeting MC4R is considered promising because it is present on nerve cells that regulate appetite and energy use.