Study to Evaluate HM15275 in Obese or Overweight Subjects Without Diabetes Mellitus

Key Inclusion Criteria 1. Participant's age at the time of signing the informed consent: * United States: 18 to 75 years (inclusive) * Korea: 19 to 75 years (inclusive) 2. BMI ≥30 kg/m² and ≤50 kg/m², or ≥27 kg/m² and \<30 kg/m² with ≥1 weight-related comorbidity 3. Body weight change \<5% over the past 3 months prior to screening 4. Capable of giving signed informed consent, ability and willingness to comply with all protocol procedures Key Exclusion Criteria: 1. Type 1 diabetes mellitus or T2DM, or HbA1c ≥6.5% / FPG ≥126 mg/dL 2. Obesity due to endocrine/genetic disorders 3. Planned or prior obesity surgery (unless \>1 year ago for liposuction/abdominoplasty), or device-based obesity therapy (unless removed \>6 months ago) 4. Personal history or current diagnosis of acute or chronic pancreatitis or factors that may increase the risk of pancreatitis, such as a history of cholelithiasis (without cholecystectomy) or alcohol abuse. 5. Personal or family history of medullary thyroid carcinoma (MTC) or a known genetic condition (e.g., multiple endocrine neoplasia type 2) that predisposes the participant to MTC. 6. Have taken weight loss drugs, including over-the-counter medications, within 90 days prior to screening. 7. History or current diagnosis of congestive heart failure (NYHA class Ⅲ or Ⅳ), or myocardial infarction, stroke, unstable angina, transient ischemic attack, or revascularization procedure (e.g., stent or bypass graft surgery) within 3 months prior to screening visit 8. Personal history or current diagnosis of acute or chronic pancreatitis or factors that may increase the risk of pancreatitis, such as a history of cholelithiasis (without cholecystectomy) or alcohol abuse.