Belantamab Mafadotin Maintenance Therapy After Salvage Autologous Hematopoietic Cell Transplantation in Patients With Relapse Refractory Multiple Myeloma

Eligibility Criteria

• 1. Patients with relapsed or refractory multiple myeloma. Eligible patients will be enrolled in the protocol no less than 60 days and must be initiated no longer than 180 days (± 2 weeks) post ASCT. Patient's transplant may be either transplantation naïve or with a history of previous autologous transplant.
• 2. Patients who have had two or more lines of therapy consisting of at least one of three agents including a proteasome inhibitor or an immunomodulatory agent or an anti-CD38 targeting therapy.
• 3. Disease status, partial response, or better.
• 4. Age ≥ 18-year and ≤ 75-year. English and non-English speaking patients are eligible.
• 5. Platelet count ≥ 50,000/mm3 \& Hemoglobin ≥ 8 g/dL, ANC ≥ 1.0 × 109/L
• 6. Karnofsky Performance Status (KPS) \>70 (Appendix B.).
• 7. Adequate organ function (ALT ≤ 2.5 ULN; Total bilirubin ≤ 1.5 ULN or total bilirubin
• * 1.5 ULN with direct bilirubin ≤ 35%; estimated glomerular filtration rate ≥30 mL/min per 1.73 m2
• 8. Participants must not be pregnant or lactating
• 9. Female participants: contraceptive use should be consistent with institutional guidelines regarding the methods of contraception for those participating in clinical studies.
• 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 \<1% per year), preferably with low user dependency (as described in Appendix C.), during the intervention period and for at least 4 months after the last dose of study intervention and agrees not to donate eggs (ova, oocytes) for reproduction during this period. The investigator should evaluate the effectiveness of the contraceptive method in relation to the first dose of the study intervention.
• * Refrain from donating sperm
• * Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent.
• 1. Current corneal epithelial disease (except mild punctate keratopathy). 2. Participant must not use contact lenses while participating in this study. 3. Ongoing Grade 2 or higher peripheral neuropathy or neuropathic pain. 4. Participants who are using an investigational drug or approved systemic anti-myeloma therapy (including systemic steroids) within 14 days or five half-lives, whichever is shorter, preceding the first dose of study drug.
• 5. Participants who have current unstable liver or biliary disease defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia (serum albumin \< 3.0 gm/dl), esophageal or gastric varices, persistent jaundice, or cirrhosis. Note: Stable non-cirrhotic chronic liver disease (including Gilbert's syndrome or asymptomatic gallstones) or hepatobiliary involvement of malignancy is acceptable if otherwise meets entry criteria 6. Participants who have presence of active renal condition (infection, requirement for dialysis or any other condition that could affect participant's safety). Participants with isolated proteinuria resulting from MM are eligible, provided they fulfil inclusion criteria 7. Participants who have received prior treatment with a monoclonal antibody within 30 days of receiving the first dose of study drugs.
• 8. Participants who have had major surgery ≤ 4 weeks before initiating study treatment.
• 9. Participants who have any evidence of active mucosal or internal bleeding. 10. Participants who have known immediate or delayed hypersensitivity reaction or idiosyncratic reactions to belantamab mafodotin or drugs chemically related to belantamab mafodotin, or any of the components of the study treatment.
• 11. Participants who have an active infection requiring treatment 12. Participants who have evidence of cardiovascular risk, including any of the following:
• * Established anti-retroviral therapy (ART) for at least 4 weeks and HIV viral load \<400 copies/mL
• * CD4+ T-cell (CD4+) counts ≥350 cells/uL
• * No history of AIDS-defining opportunistic infections within the last 12 months 14. Participant must not have presence of hepatitis B surface antigen (HBsAg), or hepatitis B core antibody (HBcAb) at screening or within 3 months prior to first dose of study treatment. Note: presence of Hep B surface antibody (HBsAb) indicating previous vaccination will not exclude a participant.
• 15. Participant must not have positive hepatitis C antibody test result or positive hepatitis C RNA test result at screening or within 3 months prior to first dose of study treatment.
• 16. Participant must not have invasive malignancies other than disease under study, unless the second malignancy has been medically stable for at least 2 years and, in the opinion of the principal investigators, will not affect the evaluation of the effects of clinical trial treatments on the currently targeted malignancy. Participants with curatively treated non-melanoma skin cancer may be enrolled without a 2-year restriction.
• 17. Prior allogeneic stem cell transplant. NOTE: Participants who have undergone syngeneic transplant will be allowed only if no history of or no currently active GvHD.
• 18. Symptomatic amyloidosis, active POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasmaproliferative disorder, skin changes) or active plasma cell leukaemia at the time of screening.
• 19. Patients with cognitive impairments and/or any serious unstable pre-existing medical condition or psychiatric disorder that can interfere with safety or with obtaining informed consent or compliance with study procedures. Informed Consent Process. The informed consent process will begin at recognition of subject eligibility, and consent will be obtained per Institutional practices before study therapy is initiated.