This is a single-center, single arm, phase I study designed to determine the safety and find the recommended Phase 2 dose (RP2D) or maximum dose level (MTD) of Belantamab Mafodotin in patients with high-risk smoldering multiple myeloma. The study will have a dose-finding part and a dose-expansion part. The maximum number of enrolled patients will be 30 with 18 patients for the dose-finding part and 12 patients for the dose-expansion part. Once we determine the MTD or RP2D in the dose-finding part, we will enroll and treat 12 additional patients at the MTD or RP2D in the expansion part. Efficacy will be assessed through the overall response rate (ORR) at the end of the study. With the limited number of patients for the dose-expansion part, we will not have formal futility monitoring rule.
Bone marrow plasmacytosis with ≥ 10% plasma cells in bone marrow biopsy
Immunoparesis (reduction in at least one uninvolved immunoglobulin in blood)
≥ 95% aberrant plasma cells of all plasma cells by flow cytometry of the bone marrow aspirate
Creatinine clearance (CrCl) ≥ 30 ml/min. CrCl will be calculated using the Modification of Diet in Renal Disease (MDRD) equation.
Hypercalcemia: serum calcium >0.25 mmol/L (>1 mg/dL) higher than the upper limit of normal or > 2.75 mmol/L (> 11 mg/dL)
Renal Insufficiency: creatinine clearance < 40 ml/min or serum creatinine > 2 mg/dL
Anemia: hemoglobin value more than 2 g/dL < normal reference
Bone lesions: one or more osteolytic lesions on skeletal radiography, computerized tomography (CT) or 2-deoxy-2[F-18] fluoro-D-glucose positron emission tomography CT (PET-CT).