Hanmi Pharm has announced it has signed an exclusive licensing agreement with Genentech covering the development, manufacturing and commercialisation of its investigational obesity therapy HM17321.
The deal (which excludes South Korea) has a potential total value of up to $2.3bn, including a $190m upfront payment, development, regulatory and commercial milestones and tiered royalties on net sales.
A different approach to weight loss therapy
HM17321 is a proprietary, long-acting urocortin-2 (UCN2) analogue that acts through the corticotropin-releasing factor 2 (CRF2) receptor rather than the incretin pathway.
Hanmi is developing the peptide as a potential first-in-class treatment for chronic weight management and associated metabolic conditions, including type 2 diabetes and cardiovascular disease.
The candidate is intended to address an emerging challenge in obesity pharmacotherapy: how to reduce adipose tissue while maintaining, or even increasing, muscle mass.
Research has shown that weight loss with GLP-1 receptor agonists can include reductions in lean mass, although the magnitude and clinical implications vary by therapy and individual.
A 2026 systematic review found that GLP-1 receptor agonist treatment was associated with a significant reduction in absolute lean mass, while lean mass as a proportion of total body weight increased.
Preclinical research from Hanmi suggests HM17321 could offer a differentiated approach.
In animal models, the candidate has demonstrated reductions in body weight and fat mass alongside increases in lean mass.
Studies have also investigated HM17321 in combination with incretin therapies, with results suggesting potential improvements in body composition compared with either treatment alone.
The underlying UCN2 pathway has previously been investigated for its role in energy balance, glucose metabolism and skeletal muscle.
Research in obese animal models has found that modified UCN2 peptides can improve skeletal muscle mass and function, providing a biological rationale for pursuing the pathway in metabolic disease.
Phase I paves the way for Genentech handover
HM17321 is currently in Phase I clinical development.
Hanmi received US FDA IND clearance in November 2025 and is responsible for completing the ongoing study, which is assessing safety, tolerability, pharmacokinetics and pharmacodynamics in healthy volunteers and people with obesity.
Genentech — a member of Roche Group —will assume development responsibility from Phase II onwards.
The agreement gives Roche and Genentech access to a non-incretin mechanism that could potentially be developed as a standalone obesity therapy or alongside existing incretin-based medicines.
However, the candidate remains investigational and whether its preclinical body-composition findings translate into clinically meaningful benefits in humans will depend on the ongoing clinical programme.
