MEDI2228 is an antibody drug conjugate (ADC) comprised of a fully human B-cell maturation antigen (BCMA) antibody conjugated to a pyrrolobenzodiazepine (PBD) dimer. This phase 1 trial evaluated MEDI2228 in patients with relapsed/refractory (R/R) multiple myeloma (MM), who received prior treatment with approved agents from 3 classes of antimyeloma drugs (proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies). Primary endpoint was safety and tolerability; secondary endpoints included efficacy, pharmacokinetics, and immunogenicity. A total of 107 patients were treated and the maximum tolerated dose (MTD) was 0.14 mg/kg Q3W. Two patients had dose-limiting toxicities (DLTs; thrombocytopenia; 0.20 mg/kg Q3W). The most frequent treatment-related adverse events were photophobia (43.9%), rash (29.0%), and thrombocytopenia (19.6%). In MTD cohort A (n = 41), the objective response rate (ORR) was 56.1%, with 1 stringent complete response, 9 very good partial responses, and 13 partial responses. ORR was 53.3% in triple refractory patients. In cohort B (n=25), ORR was 32%. Although MEDI2228 demonstrated efficacy in R/R MM, ocular toxicity precluded further development of this drug.
Keywords: Antibody drug conjugate; B-cell maturation antigen; NCT03489525; triple refractory multiple myeloma.
MEDI2228 is an ADC comprised of a fully human anti-BCMA antibody conjugated to the cytotoxic PBD payload, tesirine.MEDI2228 monotherapy demonstrated efficacy across all dose levels; and responses were observed in patients with triple refractory MM.This study further validates BCMA as a target for ADC-based therapy in MM; ocular toxicity precluded further clinical development.