Single-agent belantamab mafodotin for relapsed/refractory multiple myeloma: analysis of the lyophilised presentation cohort from the pivotal DREAMM-2 study
Paul G. Richardson, Hans C. Lee, Al-Ola Abdallah, Adam D. Cohen, Prashant Kapoor, Peter M. Voorhees, Axel Hoos, Karrie Wang, January Baron, Trisha Piontek, Julie Byrne, Scott Richmond, Roxanne C. Jewell, Joanna Opalinska, Ira Gupta, Sagar Lonial
Abstract
DREAMM-2 (NCT03525678) is an ongoing global, open-label, phase 2 study of single-agent belantamab mafodotin (belamaf; GSK2857916), a B-cell maturation antigen-targeting antibody-drug conjugate, in a frozen-liquid presentation in patients with relapsed/refractory multiple myeloma (RRMM). Alongside the main study, following identical inclusion/exclusion criteria, a separate patient cohort was enrolled to receive belamaf in a lyophilised presentation (3.4 mg/kg, every 3 weeks) until disease progression/unacceptable toxicity. Primary outcome was independent review committee-assessed overall response rate (ORR). Twenty-five patients were enrolled; 24 received ≥1 dose of belamaf. As of 31 January 2020, ORR was 52% (95% CI: 31.3-72.2); 24% of patients achieved very good partial response. Median duration of response was 9.0 months (2.8-not reached [NR]); median progression-free survival was 5.7 months (2.2-9.7); median overall survival was not reached (8.7 months-NR). Most common grade 3/4 adverse events were keratopathy (microcyst-like corneal epithelial changes, a pathological finding seen on eye examination [75%]), thrombocytopenia (21%), anaemia (17%), hypercalcaemia and hypophosphatemia (both 13%), neutropenia and blurred vision (both 8%). Pharmacokinetics supported comparability of frozen-liquid and lyophilised presentations. Single-agent belamaf in a lyophilised presentation (intended for future use) showed a deep and durable clinical response and acceptable safety profile in patients with heavily pre-treated RRMM.