P20: POLYCENTRIC “REAL LIFE” STUDY OF BELANTAMAB MAFODOTIN FOR RELAPSED/REFRACTORY MULTIPLE MYELOMA
Authors: R Iula, F Trastulli, R Della Pepa, A D’Ambrosio, M Romano, A Leone, G Gaeta, S Palmieri, S Rocco, F Pane, F Ferrara, L Catalano
Journal: HemaSphere (2022)

Background: Despite recent therapeutic advances, multiple myeloma (MM) remains an incurable disease. Particularly poor outcomes were described for “triple-refractory”patients, who are refractory to at least one proteasome inhibitor, immunomodulatory agent and anti-CD38 antibody. In this setting, we need further therapeutic options, and the DREAMM-2 study has shown interesting responses with Belantamab Mafodotin (BM). However, real-life studies are still lacking. Methods: We performed a real-life analysis in two Italian centers (AOU Federico II and AORN Cardarelli, both in Naples). Unselected triple refractory patients received BM monotherapy as part of a compassionate use program. Whole sample (WS) included patients who received at least 1 dose of BM; evaluable population (EP) included only patients receiving not less than 2 BM cycles. Primary endpoint was overall response rate (ORR, i.e rate of patients with partial response -PR- very good partial response -VGPR- or complete response –CR-). Secondary outcomes included median progression free survival (mPFS), median overall survival (mOS), clinical benefit rate (CBR, i.e. rate of patients achieving stable disease -SD- or better), duration of response (DoR), time to response (TTR), time to best response (TTBR) and toxicity. BM was i.v. infused at the dose of 2.5 mg/kg every 3 weeks until progressive disease (PD) or unacceptable toxicity. Before treatment, 20 mg i.v. dexamethasone and 10 mg i.v. chlorphenamine were administered. Each patient received ice packs on eyes throughout the drug infusion, and anti-infective and eye prophylaxis (corticosteroid and lubricant eye drops) were prescribed at home. Laboratory assessments were performed at baseline and at day 1 of each cycle. All patients underwent eye examination before the first cycle of BM and as clinically indicated thereafter. Results: Seventeen patients were treated from June 2020 to December 2021. Median age was 63 years (r.: 51-77); median time from the diagnosis was 7 years (r.: 1-19), and median number of previous lines of therapy was 7 (r.: 4-14). In the WS (17 patients), median follow-up was 7 months (r.: 0.5-18) and median number of cycles was 3 (r.: 1-18). ORR was 35%, mPFS and mOS were 3 months (r.:0.5-18) and 8 months (r.:1-18), respectively. In the EP (14/17), ORR was 43% (6/14), including 1 CR (7%) and 5 PR (36%). Two patients (14%) showed SD, with a CBR of 57% (8/14). Among responsive patients (RP), 2 patients received successfully consolidation with a second ASCT; 3 patients are to date still on treatment and 1 patient experienced PD after 3 months of PR. In the EP, mPFS and mOS were 4 months (r.: 1-18) and 11 months (r.:2-18), respectively. Among RP, DoR, mPFS and mOS were not reached, TTR was 2 months (r.: 2-8) and TTBR was 6 months (r.: 2-8). Thrombocytopenia (57%) and keratopathy (21%) were the most frequent adverse reactions. Two patients with grade 3 eye toxicity discontinued the therapy and eye damage resolved. Interpretation: Our analysis confirms the efficacy of BM and compares favorably with DREAMM-2 study (ORR: 43% vs 32%, mPFS: 4 vs 2.8 months, mOS: 11 vs 13.7 months, respectively). Moreover, we found less corneal toxicities (21% vs 72%), more thrombocytopenia (57% vs 38%) and no infusion-related reactions (0% vs 21%). In conclusion, BM shows meaningful anti-MM activity and a manageable toxicity profile even outside controlled clinical trials, proving to be an effective novel strategy in advanced MM.