A Study to Investigate the Safety and Efficacy of Belantamab for the Treatment of Multiple Myeloma When Used as Monotherapy and in Combination Treatments

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 belantamab 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 doses of belantamab in combination with a fixed dose of Belantamab mafodotin (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 belantamab in combination with the pomalidomide-dexamethasone (Pd) standard of care (SoC) backbone. The study will focus on participants with multiple myeloma who have undergone at least one prior line of therapy, including treatment with lenalidomide.