lorvotuzumab-mertansine and Multiple-Myeloma

Lorvotuzumab mertansine (LM) is an ADC composed of an anti CD56 humanized N901 monoclonal antibody conjugated via a stable disulfide linker to the maytansinoid DM1. CD56 is expressed in up to 78% of multiple myelomas. LM displays antitumor activity in preclinical models of multiple myeloma. In a phase I study of MM, the MTD of single-agent LM was 112 mg/m². The dose-limiting toxicities were grade 3 fatigue and grade 3 acute, reversible, renal failure. 2 PRs and 4 MRs were observed at various dose levels starting at 60 mg/m². Building on the single agent experience, a phase II study of LM in combination with lenalidomide and dexamethasone was conducted. The optimal dose of LM was 75 mg/m² in the combination. The ORR was 56.4%. The most common treatment-related AE was peripheral neuropathy (PN), mostly grade 2 or less, with the majority of patients having a grade 1 PN at baseline. Continued evaluation of optimal dosing levels and schedules will be important to better define the utility of this promising treatment.

Topics: Antibodies, Monoclonal; CD56 Antigen; Humans; Immunoconjugates; Maytansine; Multiple Myeloma

Despite therapeutic advancements that have significantly improved outcomes in multiple myeloma (MM), it remains an incurable disease. Patients with relapsed and/or refractory MM have an aggressive disease course, with inferior outcomes, necessitating the need for agents with novel therapeutic mechanisms. We present the results of a completed phase I trial of single-agent lorvotuzumab mertansine, a unique antibody-drug conjugate targeting CD56, which is frequently expressed in MM.. Thirty-seven patients with relapsed MM were enrolled in a dose-escalation phase I clinical trial to determine the maximum tolerated dose of lorvotuzumab mertansine (112 mg/m. Despite a high proportion of patients with relapsed and/or refractory MM (56.8%), stable disease or better was noted in 42.9% of patients, and these patients had a long duration of response (median, 15.5 months). The adverse event profile was favorable, with a low incidence of grade 3/4 adverse events and no infusion-related reactions. No humoral responses were detected against the study drug.. This completed phase I trial of single-agent lorvotuzumab mertansine provides ample evidence of safety and signals of clinical activity for this agent, warranting its further clinical development as part of combination regimens for the management of MM.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; CD56 Antigen; Female; Humans; Male; Maytansine; Middle Aged; Multiple Myeloma; Recurrence