This study will consist of 2 parts. The study will evaluate whether administration of phenytoin impacts the single-dose drug levels of afimetoran and BMT-271199 (Part 1) and will evaluate whether multiple administrations of afimetoran impact the drug levels of midazolam and 1-hydroxymidazolam (Part 2).

Inclusion Criteria:

• Body mass index (BMI) of 19.0 kilograms per meter squared (kg/m^2) to 32.0 kg/m2, inclusive, and body weight ≥ 55 kg, at screening.

Exclusion Criteria:

• Any significant acute or chronic medical illness or any other condition listed as a contraindication in the phenytoin (Part 1) or midazolam (Part 2) package inserts.
• History of seizure (including simple febrile seizure), epilepsy, severe head injury (including concussion), multiple sclerosis, or other known neurological condition which the investigator considers to be clinically significant.
• Current or recent (within 3 months of study intervention administration) GI disease that could impact upon the absorption of study intervention.

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/disclosure-commitment.html