**Study Overview:** This research tests **brenipatide**, a medication, to see if it helps people who've recently quit smoking avoid starting again. **Placebo** is a substance with no active treatment, used here for comparison. **Key Points:** - **Duration:** The study lasts about 34 weeks with around 17 visits. This includes a 2-week screening, 24-week treatment, and an 8-week safety follow-up. - **Eligibility:** Participants must have recently quit smoking and be committed to staying smoke-free. They need to attend all visits and follow study rules, including using self-injections. - **Exclusions:** Individuals with recent substance use disorders (except mild cases of some), certain suicidal thoughts or behavior, severe lung conditions, or recent participation in other clinical studies are not eligible. Participating in this study requires commitment to the full duration and agreement to use the study medication. It's important for participants to meet the eligibility criteria and be willing to follow all study guidelines.