A Study of Belantamab Mafodotin in Multiple Myeloma Participants With Normal and Impaired Hepatic Function

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 must be 18 years of age or older, at the time of signing the informed consent. * Eastern Cooperative Oncology Group performance status 0-2. * Participants with histologically or cytologically confirmed diagnosis of multiple myeloma, as defined in International Myeloma Working Group criteria: Has failed at least 1 prior line of anti-myeloma * Participants has measurable disease with at least one of the following: Serum M-protein greater than or equal to (\>=)0.5 grams per deciliter (g/dL) \>=5 grams per liter \[g/L\]); Urine M-protein \>=200 milligram per 24 hours (mg/24 hr); and Serum free light chain assay: Involved free light chain level \>=10 milligrams per deciliter (mg/dL) (\>=100 milligrams per liter \[mg/L\]); abnormal serum free light chain ratio (\<0.26 or \>1.65); participants with plasmacytoma and otherwise non-measurable disease * 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 below: Absolute neutrophil count \>=1.0 times 10\^9/liter (L); H…