A Phase 1, First-in-Human Study of BMS-986421 in Healthy Participants

Inclusion Criteria: * Participants are required to remain in the clinical facility from Day -1 (Part 1) or Day -2 (Part 2) until clinic discharge. * A negative test for COVID-19, which will be performed in the manner mandated by the clinical site where this study is being conducted, at screening and admission. * All female participants, Women of Childbearing Potential (WOCBP) and women not of childbearing potential, must have a negative highly sensitive serum pregnancy test (minimum sensitivity 25 IU/L or equivalent units of human chorionic gonadotropin (HCG)) at screening and on Day -1 (or Day -2 for Part 2). Exclusion Criteria: * Participant was exposed to an investigational drug (new chemical entity) within 30 days preceding the first dose administration, or 5 half-lives of that investigational drug, if known (whichever is longer). * Vaccination or plans for vaccination with non-live vaccines within 30 days before Day -1 (for Day -2 for Part 2) until the follow-up phone call. * Donation of blood or blood transfusion within 8 weeks of first study intervention administration.