A Study of Belantamab Mafodotin Monotherapy in Multiple Myeloma Participants With Normal and Varying Degree of Impaired Renal Function

Belantamab mafodotin is an antibody-drug conjugate (ADC) containing humanized anti- B-cell maturation antigen (BCMA) monoclonal antibody (mAb). Renal impairment is a major complication of multiple myeloma (MM) and the majority of MM participants is either at risk or already has renal dysfunction at initial diagnosis. The purpose of this study is to assess the pharmacokinetics (PK), safety, and tolerability of belantamab mafodotin monotherapy in participants with RRMM, who have had at least 3 lines of prior treatment (or at least 2 lines of prior treatment if ineligible for autologous stem cell transplantation ) and have either normal or impaired renal functions. The study will consist of two parts: part 1 will include participants with normal/mildly impaired renal function and severe renal impairment and part 2 will include participants with end-stage renal disease (ESRD), where participants are either not undergoing or require hemodialysis. Participants will be administered belantamab mafodotin at a dose of 2.5 milligram per kilogram (mg/kg) intravenously once in three weeks (Q3W) dosing in Part 1. Based on the Part 1 Safety/Pharmacokinetic (PK) data, Part 2 participants will be administered the dose of either 2.5 mg/kg or 1.9 mg/kg (or other adjusted dose). Participants will be treated with belantamab mafodotin monotherapy until confirmed disease progression, death, unacceptable toxicity, withdrawal of consent, or end of study, whichever occurs first. This study will include a screening phase, treatment phase, follow-up phase and a post analysis continued treatment (PACT) phase . The total duration of the study is approximately up to 48 months.

Inclusion Criteria: * Participants are capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the Informed Consent Form. * Male and/or female participants must be 18 years of age or older, at the time of signing the informed consent. In Republic of Korea, participants must be 19 years of age or older at the time of signing informed consent. * Eastern Cooperative Oncology Group (ECOG) performance status 0-2. * Participants with histologically or cytologically confirmed diagnosis of MM, as defined in International Myeloma Working Group criteria: 1. Has undergone autologous stem cell transplant (SCT) or is considered transplant-ineligible; 2. Has failed at least 2 prior lines of anti-myeloma treatments, including an immunomodulatory drug (example \[e.g.\], lenalidomide or pomalidomide) and a proteasome inhibitor (e.g., bortezomib, ixazomib or carfilzomib). In Republic of Korea, participants should also have relapsed or refractory disease after treatment with an anti-CD38 antibody, if accessible to patients, or other suitable local standard of care. * Participants have measurable disease with at least one of the following: Serum M-protein \>=0.5 grams per deciliter (g/dL) (\>=5 grams per liter \[g/L\]); Urine M-protein \>=200 milligrams (mg) per 24 hours (mg/24 h); and Serum free light chain (FLC) assay: Involved FLC level \>=10 milligrams per deciliter (mg/dL) (\>=100 milligrams per liter \[mg/L\]) and an abnormal serum FLC ratio (\1.65). * Participants with a history of autologous SCT are eligible for study participation provided the following eligibility criteria are met: 1. Transplant was \>100 days prior to study enrollment, 2. No active infection(s), and 3. Participant meets the remainder of the eligibility criteria outlined in this protocol. * Participants with adequate organ system functions as defined follows: Absolute neutrophil count \>=1.0 x 10\^9 per liter (/L); Hemoglobin \>=7.0 g/dL or 4.9 millimoles per liter (mmol/L); Platelets \>= 50 x 10\^9/L; Total bilirubin \=1.5 x ULN is acceptable if bilirubin is fractionated and direct bilirubin \