The purpose of this study is to evaluate the safety, tolerability, drug levels and drug effect of BMS-986278 in healthy adult participants and Japanese participants.

Inclusion Criteria:

• Participants in the Japanese cohort (Part 2) must be first generation Japanese (born in Japan, not living outside of Japan > 10 years, both parents ethnically Japanese).
• Body mass index (BMI) of 18.0 kilogram (kg)/meter (m)^2 through 32.0 kg/m^2, inclusive. BMI = weight (kg)/(height [m])^2.
• Body weight ≥ 50 kg for males and ≥ 45 kg for females.

Exclusion Criteria:

• Any significant acute or chronic medical illness.
• Any gastrointestinal (GI) disease or surgery (including cholecystectomy) or other procedures (for example, bariatric procedures) that could affect drug absorption, distribution, metabolism, and excretion.
• Any major surgery within 4 weeks of first study intervention administration.

Other protocol-defined inclusion/exclusion criteria apply.

BMS will provide access to individual anonymized participant data upon request from qualified researchers, and subject to certain criteria. Additional information regarding Bristol Myers Squibb's data sharing policy and process can be found at: https://www.bms.com/researchers-and-partners/clinical-trials-and-research/disclosurecommitment.html