REAL LIFE EXPERIENCE WITH BRENTUXIMAB VEDOTIN: THE ITALIAN STUDY ON 234 RELAPSED/REFRACTORY HODGKIN'S LYMPHOMA

Abstract

Introduction: Data from phase III studies may not be sufficient to determine the whole description of a drug in routine use: the assessment of drugs during daily clinical practice may reveal evidence of additional side effects or change in efficacy, trigging sometimes withdrawal or changing indication. Observational studies can be an objective way of mapping risks in the real life. Despite the known potential bias of all the retrospective observational studies, reports on the real life experience in lymphoma patients make an important contribution to medical knowledge prior to market authorization and widespread utilization. Methods: A large Italian multicenter observational retrospective study was conducted on the use of brentuximab vedotin (BV) for patients with relapsed Hodgkin's lymphoma (HL) in the everyday clinical practice according to an Italian national law (Law 648/96: “medicinal products that are provided free of charge on the national health service” active for BV from November 2012 to July 2014”) to check if clinical trial results are confirmed even in a real life context. Primary endpoint was the best response; secondary endpoints were the overall response rate at the end of the treatment, duration of response, survival, and the safety profile. Results: Two hundred thirty-four CD30+ HL patients were treated. Best response was observed after a median of 4 cycles in 140 patients (59.8%): 74 (31.6%) patients obtained a complete response (CR) and 66 (28.2%) achieved a partial response (PR); overall response rate at the end of the treatment was 48.3% (62 CR and 51 PR). The best response rate was higher in the elderly subset (>60 y): 14 (50%) CR and 5 (17.8%) PR. Disease free survival was 26.3% at 3 years and progression free survival 31.9% at 4.5 years. We identified 30 long-term responders (patients with a response ≥12 months) of whom 18 are still in CR, 7 with a consolidative SCT, and 11 without any consolidative procedure. Duration of response did not differ who achieved at least PR and then either did or did not undergo consolidative SCT. Overall, the treatment was well tolerated in everyday clinical practice, and the toxicity profile was closely similar to the previously published data; no death has been linked to BV-induced toxicity. Conclusions: The results of this large retrospective study of 234 relapse/refractory HL in the daily practice support the BV efficacy with manageable toxicity superimposable to the one reported in clinical trials results; in particular, there is the confirmation of the similar activity in different settings, eg, in elderly patients, and of the response duration independently by the transplant consolidation. The relevance of the CR status after 4 cycles and the role of BV as a bridge to ASCT for the chemorefractory patients were also pointed up. Keywords: brentuximab vedotin; Hodgkin lymphoma (HL)