Hanmi Pharm, the core business unit of Hanmi Science, has initiated a Phase 1 clinical trial for HM17321, a novel obesity drug candidate designed to achieve weight loss while increasing muscle mass — a first-of-its-kind approach, the company announced.
On Nov. 4 (U.S. local time), Hanmi said the U.S. Food and Drug Administration (FDA) cleared the investigational new drug (IND) application for HM17321 (development name LA-UCN2). The Phase 1 study will evaluate safety, tolerability, pharmacokinetics and pharmacodynamics in healthy adults and patients with obesity.
Unlike existing GLP-1–based therapies that primarily focus on weight reduction and often accompany muscle loss, Hanmi positions HM17321 as a potential "game changer" by selectively reducing fat while promoting muscle gain through a distinct mechanism of action.
HM17321 is a peptide analogue of urocortin‑2 (UCN2) that selectively targets the corticotropin‑releasing factor 2 (CRF2) receptor rather than incretin receptors. Hanmi said the candidate was designed using the company’s in‑house AI and structural modeling capabilities. Because CRF‑family signaling is linked to stress response and recovery, selective CRF2 activation is expected to directly drive fat loss, muscle hypertrophy and improvements in muscle function.
Hanmi also highlighted HM17321’s potential as both a standalone therapy and a combination partner. Preclinical data suggest the candidate can deliver superior quantitative and qualitative weight‑loss effects when combined with incretin‑class drugs. As a peptide, HM17321 offers dosing convenience and cost advantages; when paired with peptide‑based incretin agents, it could enable co‑administration, improving patient convenience.
The company contrasted HM17321 with antibody‑based muscle‑preserving treatments that typically require intravenous administration and have limited functional benefits. Hanmi said HM17321’s peptide format and delivery options (e.g., subcutaneous) may offer better usability and potential functional improvements.
HM17321 is part of Hanmi’s Hanmi Obesity Pipeline (H.O.P.), a six‑program initiative employing multi‑mechanistic, differentiated strategies. Hanmi recently reported promising interim topline results from the Phase 3 program of its first H.O.P. candidate, efpeglenatide, citing strong efficacy and a favorable safety profile as foundations for a mass‑market obesity drug. A second H.O.P. program, HM15275 (LA‑GLP/GIP/GCG), filed an IND for Phase 2 with the FDA in July and is being developed toward a 2030 commercialization goal.
Preclinical efficacy and mechanistic studies using overweight and obese nonhuman primate models have supported HM17321’s clinical potential, Hanmi said. The company plans to accelerate development across the organization with an aim to bring HM17321 to market by 2031.
Choi In‑young, head of Hanmi’s R&D Center, said, “HM17321 is not merely a weight‑loss drug; it aims to simultaneously deliver fat reduction, muscle gain, and improvements in exercise and metabolic function, fundamentally differentiating it from existing therapies. Hanmi will treat obesity as a metabolic disease rather than a numbers game on a scale, and pursue patient‑centric, personalized solutions.”
