Study of Belantamab Mafodotin as Pre- and Post-autologous Stem Cell Transplant and Maintenance for Multiple Myeloma

This is a single-institution, single-arm, phase 2 study in which belantamab mafodotin (GSK2857916), an antibody-drug conjugate targeting B-cell maturation antigen (BCMA), will be administered to patients with multiple myeloma prior to and following high-dose melphalan and autologous stem cell transplantation (ASCT), in conjunction with standard lenalidomide maintenance. We hypothesize that administration of belantamab mafodotin as part of autologous stem cell transplant consolidation and maintenance will be safe, well tolerated, and efficacious in comparison to historical data.

Inclusion Criteria: 1. Must be able to understand the study procedures and have signed written, informed consent. 2. Must be 18 years of age or older at enrollment. 3. Must have started therapy for active multiple myeloma within 12 months of enrollment. 4. Must have an ECOG performance status of 0-2. 5. Have received no more than 2 prior lines of induction therapy (induction regimen not specified by protocol), with no prior progressive disease by International Myeloma Working Group (IMWG) criteria. 6. Must be in at least a partial response (PR) but not in a complete response (CR) or better after at least 4 cycles of induction therapy, per IMWG consensus criteria. 7. Eligible by institutional criteria to receive melphalan at a dose of 200 mg/m2. 8. Eligible to receive lenalidomide maintenance therapy post-ASCT. 9. Adequate bone marrow and organ function at enrollment. 10. A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: 1. Is not a woman of childbearing potential (WOCBP), OR 2. Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of \