A Single and Multiple Ascending Dose Study of HM17321 in Healthy and Obese Participants

This is a Phase 1, randomized, double-blind, placebo-controlled, single and multiple ascending dose study designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of HM17321, a urocortine 2 (UCN2) analog, administered by subcutaneous (SC) injection in healthy and obese participants. The study consists of two parts: Part A (Single Ascending Dose) and Part B (Multiple Ascending Dose), with approximately 90 participants to be enrolled in total. In Part A, approximately 40 healthy participants with a body mass index (BMI) of ≥20 kg/m² and ≤27 kg/m² will be enrolled across 5 sequential dose cohorts. Each cohort will consist of approximately 8 participants randomized in a 6:2 ratio to receive a single SC dose of HM17321 or placebo. A sentinel dosing strategy will be applied in each cohort to ensure participant safety, with initial safety data reviewed prior to dosing the remainder of the cohort. Dose escalation decisions will be made by a Safety Review Committee (SRC) based on safety, tolerability, and available PK data. Part A will include a screening period of up to 28 days, a 5-day inpatient stay with single SC dosing, and an outpatient follow-up period through Day 29, with an overall study duration of approximately 8 weeks per participant. In Part B, approximately 50 healthy obese participants with a BMI of ≥30 kg/m² and ≤45 kg/m² will be enrolled across 5 sequential dose cohorts. Each cohort will consist of approximately 10 participants randomized in an 8:2 ratio to receive once-weekly SC doses of HM17321 or placebo over a 12-week treatment period. Dose escalation will be guided by SRC review of safety, tolerability, and PK data at predefined time points. Part B will include a screening period of up to 45 days, a 12-week treatment period with once-weekly SC dosing, and a 4-week follow-up period through Day 113, with an overall study duration of approximately 22 weeks per participant.