A 2-part, Phase 1b Clinical Study Designed to Evaluate the Safety, PK, and Efficacy of CRB-913 in Participants With Obesity

Prior treatment

• Bariatric surgery or \>5 kg weight change in past 3 months
• Recent use (within 3 months) of GLP-1 agonists or other weight-loss medications
• Abnormal thyroid function: TSH \>6 mIU/L unless stable on replacement therapy
• Use of CYP3A4 substrates or strong P-gp substrates/inhibitors
• Investigational drug use within 28 days
• Prior exposure to CRB-913 or other CB1 inverse agonists/antagonists
• Positive drug or alcohol screen

Other illness

• Significant liver disease or moderate-severe hepatic impairment
• History of seizures, epilepsy, or intracranial surgery
• Diabetes mellitus (Type 1 or Type 2), except gestational
• Any history of suicidal ideation/attempt
• Severe psychiatric disorders (e.g., schizophrenia, bipolar disorder)
• Active or recent (within 5 years) malignancy (exceptions: in situ and fully resected nonmelanoma skin cancer)
• Any condition that, in the investigator's judgment, makes participation unsafe or non-feasible

Lab values

• QTc \>470 msec (females) or \>450 msec (males) or history of long QT syndrome
• Use of systemic corticosteroids or unstable chronic medications affecting BP, lipids, or glucose

Other

• Major depression within 2 years.
• Elevated screening scores: PHQ-9 \>4, GAD-7 \>4, or positive C-SSRS Items 1-2
• Substance abuse history
• Pregnancy, breastfeeding, or unwillingness to use highly effective contraception

• Part 1: Participants with BMI 18.0-25.0 kg/m²
• Part 2: Obese participants with BMI ≥30 kg/m²