Comparable safety profile of BeEAM (bendamustine, etoposide, cytarabine, melphalan) and BEAM (carmustine, etoposide, cytarabine, melphalan) as conditioning before autologous haematopoietic cell transplantation

Introduction
BEAM (carmustine, etoposide, cytarabine, melphalan) is the most frequently used high-dose chemotherapy regimen for patients with lymphoma referred for autologous haematopoietic cell transplantation (autoHCT). Recently, a novel conditioning protocol containing bendamustine instead of carmustine (BeEAM) has been proposed to potentially increase the efficacy.

Aim of the study
The aim of this study was to retrospectively compare the safety profile of BEAM and BeEAM based on single-centre experience.

Material and methods
A total of 237 consecutive patients with lymphoma treated with either BEAM (n = 174) or BeEAM (n = 63), between the years 2011 and 2016, were included in the analysis. Clinical characteristics of both groups were comparable. Patients with Hodgkin’s lymphoma (HL) constituted 49% of the BEAM group and 40% of the BeEAM group.

Results
Median time to neutrophil > 0.5 × 109/l recovery was 10 days in both groups (p = 0.29), while median time to platelet > 50 ×109/l recovery was 13 and 14 days after BEAM and BeEAM, respectively (p = 0.12). The toxicity profile was comparable except for arterial hypertension and severe hypokalaemia, which occurred more frequently after BeEAM compared to BEAM (p = 0.02 and p = 0.004, respectively). The rate of early mortality was 1.7% and 1.6%, respectively. The probabilities of the overall and progression-free survival were comparable for both groups (p = 0.73 and p = 0.55, respectively).

Conclusions
Administration of bendamustine instead of carmustine as part of conditioning does not affect the engraftment or the toxicity profile of the regimen. Therefore, BeEAM may be safely used in patients with lymphoma undergoing autoHCT. Its efficacy requires evaluation in prospective studies.