Italian Real Life Experience with Brentuximab Vedotin: Results of a National Observational Study on Relapsed/Refractory Hodgkin's Lymphoma

From November 2012 to July 2014, brentuximab vedotin (BV) was available in Italy for patients with relapsed Hodgkin's lymphoma (HL) outside a clinical trial context based on a local disposition of the Italian Drug Agency (AIFA) issued according to a national law (Law 648/96: "medicinal products that are provided free of charge on the national health service"). A large Italian observational retrospective study was conducted on the use of BV in the everyday clinical practice 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. BV was infused intravenously at the dose of 1.8 mg/kg every 3 weeks. A total of 234 HL patients were treated in 40. All patients had histologically documented CD30+ HL; 49% had relapsed and 51% had refractory disease. Patients were heavily pretreated with a median of 3 previous therapies (including autologous stem cell transplant [SCT] in the 69% of cases). 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 years): 14 (50%) CR and 5 (17.8%) PR. Disease free survival was 26.3% at 29 months and progression free survival 31.9% at 55 months. 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. All patients were included in the safety profile for the analysis; in general, 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. This preliminary analysis could indicate that BV displays a number of features favoring its use as a bridge to transplant in patients with active disease who achieve a suboptimal response to salvage treatment. Even in a real life context, BV induces clinical responses quite rapidly, i.e. within the first 4 cycles in most responders, thus permitting the timely application of the transplantation phase. BV displays a favorable toxicity profile, without overlapping toxicities with most of the agents employed in high-dose conditioning regimens. Furthermore, for HL patients ineligible for transplant or for who transplant failed, may represent a feasible effective therapeutic option.