A Phase 1/2 Open-label, Multicentre, Dose Escalation and Expansion Study to Investigate the Safety, Tolerability, and Clinical Activity of Belantamab as Monotherapy and in Combination With Other Treatments in Participants With Multiple Myeloma

The study consists of three parts: * Part 1 The primary purpose of this part aims to evaluate the safety, tolerability, and clinical activity of escalating doses of single agent Unconjugated belantamab antibody in participants with refractory multiple myeloma (RRMM) who have received at least 3 prior therapies (4L+). * Part 2 The primary purpose of this part is to evaluate the safety, tolerability, and clinical activity of different dose ratios of belantamab mafodotin in combination with Unconjugated belantamab antibody (delivered as separate drugs) in participants with RRMM who have received at least 3 prior therapies (4L+). * Part 3: The Primary purpose of this part will evaluate the clinical activity of a selected dose of the unconjugated belantamab antibody, either alone or in combination with belantamab mafodotin alongside the standard of care (SoC) pomalidomide-dexamethasone backbone. The study will focus on patients with multiple myeloma who have undergone at least one prior line of therapy, including treatment with lenalidomide.