Real-Life Experience with Brentuximab Vedotin (Adcetris®): the Belgian National Registry
Authors: Verhoef Gregor , Andre Marc , Imschoot Johan , Graas Pamela , Bron Dominique 
Published: October 2019

Abstract
Real-Life experience with brentuximab vedotin (Adcetris®): the Belgian National Registry
Introduction: Brentuximab vedotin (BV) was reported to be effective and safe against refractory/relapsed (r/r) systemic anaplastic large cell lymphoma (sALCL) and Hodgkin lymphoma (HL) in cohorts of 12 to 102 patients. A Registry was opened in all the academic centers in Belgium, on the 1st of November 2014. We report our retrospective analysis of the Belgian experience of brentuximab vedotin used alone in CD30+ HL and sALCL
Population and methods: 38 patients (30 r/r HL and 8 r/r sALCL patients, all CD30+) in 12 Belgian academic centers, were included in a non-interventional Registry and retrospectively analysed to evaluate the real-life experience with Adcetris® in Belgium. BV was administered intravenously (IV) at a dose of 1.8mg/kg (max. 180mg) every 3 weeks for 8 to 16 cycles or until progression or intolerance. The primary objective was to provide the therapeutic value of Adcetris®, as a reimbursed drug, in Belgium. Clinical endpoints were best responses and safety profiles.
Results: Between 1 November 2014 and 12 April 2016, a total of 38 patients (30 r/r HL and 8 r/r sALCL patients, all CD30+) were enrolled in this Registry. BV was used as monotherapy after a range of 1 to 5 prior chemotherapy lines in the sALCL-patients and after a range of 1 to 7 prior chemotherapy lines in the HL-patients. Patients received a median of 4 cycles. Response was assessed in 23 patients in which the Objective Response Rate (ORR= CR+PR) was 69,6%, including 26% CR. Four patients died during the observation period, however without clear relationship to the treatment with Adcetris®. Adcetris® had an acceptable toxicity: Grade-2/3 polyneuropathy (PN) occurred in 5% of the patients. The results observed in this heavily pretreated patient cohort are similar to those obtained in the pivotal phase II trials. In this cohort, 25 (83,3%) HL patients did not undergo stem cell transplant (SCT) prior to treatment with BV, which indicates more resistant disease than that of patients in the phase II trial, where 102 (100%) of patients underwent SCT prior to treatment with BV. In 4 patients, Adcetris was used as "bridge to (subsequent) transplant". These four patients achieved CR prior to their subsequent SCT. BV -as a targeting agent- is thus an appropriate treatment to prepare patients to SCT. Indeed, better results and lower organ toxicity are observed after treatment with SCT when patients are in CR before transplant.
Best response with Adcetris was evaluated in 14 non-transplanted HL-patients in which the ORR was 57,1 % and in 6 non-transplanted sALCL-patients in which the ORR was 66,7%.
Reason for discontinuation was reported in 13 non-transplanted HL-patients, in which 3 (23,1%) patients died and 10 (77%) patients progressed under treatment and in 6 non-transplanted sALCL-patients, in which 1 (16,7%) patient died, 3 (50%) patients progressed under treatment, 1 (16,7%) patient received 16 reimbursed cycles of brentuximab vedotin and 1 (16,7%) patient discontinued due to tolerance.
Conclusion: This retrospective real-life survey support previously reported data on BV in terms of efficacy and toxicity. CR can be obtained in a short timeframe in a large proportion of CD30+ HL and sALCL patients. This therapeutic BV approach, used as a "bridge to transplant", allows new promises in terms of cure in heavily pretreated CD30+lymphomas.

Disclosures
Imschoot: Takeda Belgium: Employment. Graas:Takeda Belgium: Employment.