AZD0305 as Monotherapy or in Combination With Anticancer Agents in Participants With Multiple Myeloma

This study will follow a modular protocol design evaluating AZD0305 as monotherapy and in combination with other anticancer agents. The protocol may be amended in the future to incorporate further monotherapy expansion at the recommended Phase 2 dose (RP2D) in Phase II, and/or additional modules investigating AZD0305 in combination with other anticancer agents. The study consists of 3 modules: * Module 1 (AZD0305 monotherapy), * Module 2 (AZD0305 in combination with elranatamab) * Module 3 (AZD0305 in combination with pomalidomide and dexamethasone \[Pd\])