A Study to Evaluate Preventive Treatments for GPRC5D-related Oral Events

Inclusion Criteria: * Multiple myeloma (MM) according to IMWG diagnostic criteria * Were triple-class exposed (received prior treatment with a PI, an IMiD, and anti CD38 mAb) * Documented evidence of progressive disease based on investigator's determination of response by IMWG criteria on or after their last regimen * Have an Eastern Cooperative Oncology Group-performance status (ECOG-PS) of 0 or 1 at screening. Participants with ECOG-PS 2 or 3 are eligible for the study if the ECOG-PS score is related to stable physical limitations (e.g., wheelchair-bound due to prior spinal cord injury) and not related to multiple myeloma or associated therapy * Be willing and able to adhere to the lifestyle restrictions specified in the protocol Exclusion Criteria: * Contraindications or life-threatening known allergies, hypersensitivity, or intolerance to any study drug or its excipients * Stroke, transient ischemic attack, or seizure within 6 months prior to screening * Any of the following within 6 months prior to the first dose of study treatment: severe or unstable angina, myocardial infarction; major thromboembolytic event (e.g., pulmonary embolism, cerebrovascular accident), clinically significant ventricular arrythmia or heart failure New York Heart Association functional classification Class III or IV. Uncomplicated deep vein thrombosis is not considered exclusionary * Major surgery or had significant traumatic injury within 2 weeks prior to the start of administration of study treatment, or will not have fully recovered from surgery, or has major surgery planned during the time the participant is expected to be treated in the study or within 2 weeks after administration of the last dose of study treatment * A WETT score indicating severe dysgeusia at screening and confirmed prior to randomization. Also unresolved/severe dysgeusia referred by the participant or a finding in the physical examination/oral cavity inspection. Some examples include leukoplakia, prior mouth cancers, extensive dental caries, severe periodontitis, active oral infections, candidiasis, parotic gland removal, or radiotherapy with resultant xerostomia