Benda-BEAM High-Dose Therapy Prior to Auto-SCT Is Effective in Resistant/Relapsed DLBCL

Background: The most important drawback of clinical trials of high-dose therapy (HDT) followed by autologous stem cell transplant (ASCT) in lymphomas is the high heterogeneity of histological entities. Therefore, the statistical power is reduced, and data are not conclusive. We previously demonstrated the safety of a new conditioning regimen with bendamustine, etoposide, cytarabine, and melphalan (BeEAM) prior to ASCT in resistant/relapsed lymphoma patients. This combination of drugs was able to induce a high CR rate in a population that did not have an opportunity of being cured with other therapies. However, that study enrolled both Hodgkin and non-Hodgkin lymphoma patients.

Aims: We designed a phase II study to evaluate the efficacy of the BeEAM conditioning in resistant/relapsed diffuse large B-cell non-Hodgkin lymphoma (DLBCL) patients.

Patients and methods: The study was registered at European Union Drug Regulating Authorities Clinical Trials (EudraCT) N. 2011-001246-14. Until now, 61 patients (median age 54 years, range 19-69) with resistant/relapsed DLBCL were enrolled. The primary end-point of the study is to evaluate the 1-year complete remission rate.

Results: Briefly, 46/61 patients had advanced stage disease (III-IV); 20 were primary refractory and 41 had relapsed after a median number of 2 lines of therapy (range: 1-3). Twenty-one patients had 1 or more relevant comorbidities (range: 1- 5). 30 patients were in II or subsequent CR after salvage therapy, whereas 27 were in PR and 4 had stable or progressive disease. A median number of 5.72x10⁶ CD34+/kg cells (range 2.21-10.60) collected from peripheral blood was reinfused to patients. All patients engrafted, with a median time to ANC>0.5x10⁹/l of 10 days. Median times to achieve a platelet count >20x10⁹/l and >50x10⁹/l were 12 and 17 days respectively. Twenty-two out of 61 patients presented a fever of unknown origin (36%), whereas 24 patients (39%) presented a clinically documented infection. All patients received G-CSF after transplant for a median time of 8 days (range: 8-13). One patient died due to an incomplete hematological recovery after transplant, producing an overall transplant related mortality of 2.7%. Fifty-seven patients are evaluable for response: 48/57 (84%) obtained a CR, 3/57 (5%) a PR, whereas 6/57 (11%) did not respond to therapy. After a median follow-up of 10.5 months after transplant (range 3-37), 6/57 (11%) patients were refractory, 12/57 (21%) relapsed and 39/57 (68%) are still alive, in continuous CR.

Conclusion: Our clinical trial was designed to closely resemble real-world treatment for these patients. During the study, we transplanted a similar proportion of the patients that would have received ASCT in a real-world scenario. While we cannot make sound comparisons without head-to-head trials, results from previous studies using HDT regimens in DLCBL have not been as encouraging as ours. Accordingly, our data preliminary provide the evidence that the Benda-BEAM regimen is safe and has promising high efficacy in resistant-relapsed aggressive DLBCL patients.

Acknowledgments: The study was supported in part by AIL Pesaro Onlus. Mundipharma Italy is grateful acknowledged for providing Bendamustine free of charge.