A Study to Assess BMS-986453 in Participants With Relapsed and/or Refractory Multiple Myeloma

Inclusion Criteria: * Participants must have a diagnosis of multiple myeloma with relapsed and/or refractory disease. * Participants must have confirmed progressive disease on or within 12 months (measured from the last dose) of completing treatment with the last anti-myeloma treatment regimen before study entry. * Participants in Part A and Part B Cohort 1 and in Part B Cohort 2 must have relapsed/refractory multiple myeloma and received previous antimyeloma therapy, including a proteasome inhibitor and an immunomodulatory agent. * Participants must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Participants must have adequate organ function. Exclusion Criteria: * Participants must not have any known active or history of central nervous system (CNS) involvement of multiple myeloma. * Participants must not have active or history of plasma cell leukemia, Waldenstrom's macroglobulinemia, POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome, or clinically significant amyloidosis. * Participants must not have a history or presence of clinically significant CNS pathology such as seizure disorder, aphasia, stroke, severe brain injury, dementia, Parkinson's disease, or cerebellar disease, or presence of clinically active psychosis. * Other protocol-defined inclusion/exclusion criteria apply.