Roche Pays $190M Upfront for Hanmi's Lean-Muscle-Preserving Obesity Drug

Roche (RHHBY) is paying $190 million upfront to license Hanmi Pharm’s HM17321, an experimental obesity drug that targets the biggest remaining weakness of GLP-1 therapies: muscle loss. Under the deal announced August 24, Roche’s Genentech unit gains worldwide rights outside South Korea, with development, regulatory, and commercial milestones that could push the total value to roughly $2.3 billion plus tiered royalties.

HM17321 is a urocortin-2 (UCN2) analog, not an incretin. It binds the CRF2 receptor to reduce fat mass while preserving, and in preclinical models improving, lean body mass. That matters because drugs like Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound shed fat and muscle together, a tradeoff drawing more scrutiny as the obesity market matures. UCN2 is a signaling protein that runs high in chronic heart failure, and researchers have known for decades that it can curb muscle atrophy. Roche is betting Hanmi’s version can finally deliver on that promise.

Obesity affects more than 40% of US adults, and GLP-1 drugs have turned weight loss into the industry’s biggest category, with some forecasts putting annual sales above $100 billion by the early 2030s. The loss of lean mass, which can approach a quarter of total weight shed on some incretin therapies, has become the key unresolved problem. Roche’s move follows a broader scramble among large drugmakers to add non-incretin obesity mechanisms as the GLP-1 leaders defend their franchises.

Hanmi keeps control of the ongoing Phase 1 study in healthy volunteers and people with obesity, then hands development to Genentech at Phase 2. Roche plans to study HM17321 in obesity plus type 2 diabetes and cardiovascular disease. In preclinical work, the drug improved weight reduction both alone and combined with GLP-1 therapies.

The deal extends a two-pronged obesity bet at Roche. It already owns enicepatide (CT-388), the GLP-1/GIP incretin acquired through the Carmot Therapeutics buyout that posted 22.5% weight loss in Phase 2. HM17321 adds a non-incretin complement aimed at body composition rather than pounds alone. The thesis: the next fight after the GLP-1 era is quality of weight loss, not just the number on the scale.

The caveat is straightforward. HM17321 is Phase 1, years from any filing, and the obesity market is already crowded with late-stage incretin programs from Novo and Lilly. Roche’s record here is uneven: it killed acmopatide in July, leaving enicepatide as the lead. What to watch next: Hanmi’s Phase 1 readout, which will show whether the lean-mass preservation holds in humans.

Source: Hanmi Pharm press release