Efficacy and Safety of Ribupatide Administered Once Weekly Compared With Semaglutide and Placebo in Participants Living With Obesity Who Do Not Have Diabetes

The primary objective of this study is to demonstrate that ribupatide (KAI-9531) subcutaneous (SC) injection once weekly is superior to semaglutide SC once weekly and to placebo SC once weekly on percent change in body weight.

Key Inclusion Criteria: * BMI ≥35 kilograms per square meter (kg/m\^2). * History of being unresponsive to at least 1 self-reported effort to lose weight with diet and/or exercise in the last 6 months. Key Exclusion Criteria: * Current diagnosis or history of diabetes mellitus. * Started medications within 3 months prior to Screening that may cause significant weight change, including, but not limited to, tricyclic antidepressants, atypical antipsychotics, mood stabilizers, and phentermine. * Unstable weight defined as self-reported change in body weight exceeding 5% within the 3 months prior to Screening. * Family or personal history of multiple endocrine neoplasia Type 2 or medullary thyroid cancer. * Uncontrolled hypertension or unstable cardiovascular disease. * History of chronic or acute pancreatitis. * Known clinically significant gastric-emptying abnormality or chronic treatment with medications that directly affect gastrointestinal motility. * History of suicide attempt. * History of significant active or unstable Major Depressive Disorder (MDD) or other severe psychiatric disorder. * Received treatment with semaglutide, tirzepatide, glucagon-like peptide-1 receptor (GLP-1R) agonist, GLP-1/glucose-dependent insulinotropic polypeptide (GIP), or glucagon receptor agonist within 3 months prior to Screening. Note: Additional inclusion/exclusion criteria may apply, per protocol.