Impact of Implementing a Bendamustine-Based Conditioning Regimen on Outcomes of Autologous Stem Cell Transplantation in Lymphoma while Novel Cellular Therapies Emerge

BendaEAM versus BEAM as conditioning regimen for ASCT in patients with relapsed lymphoma (BEB): a multicentre, randomised, phase 2 trial

Background

Replacement of carmustine (BCNU) in the BEAM regimen (BCNU, etoposide, cytarabine, melphalan) with bendamustine (BendaEAM) before autologous stem cell transplantation (ASCT) is feasible in lymphoma. However, randomised trials are lacking. Here, we present the first trial addressing this topic.

Methods

This multicentre, randomised, phase 2 study (BEB-trial) conducted at four haematological centres in Austria and Switzerland compares BEAM with BendaEAM in patients with relapsed lymphoma. Both regimens were administered intravenously before ASCT, in BEAM according to the standard protocol (300 mg/m2 BCNU on day -6), in BendaEAM, BCNU was replaced by 200 mg/m2 bendamustine given on days -7 and -6. Eligible patients were aged 18-75 years and had mantle cell lymphoma, diffuse large B-cell lymphoma, or follicular lymphoma in first or second remission or chemosensitive relapse. The primary endpoint of the study was to evaluate whether replacement of BCNU by bendamustine reduces lung toxicity, defined as a decrease of the diffusion capacity of the lung for carbon monoxide by at least 20% at three months after ASCT. Data analyses were performed on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT02278796, and is complete.

Findings

Between April 20, 2015, and November 28, 2018, 108 patients were enrolled; of whom 53 were randomly assigned to receive BendaEAM (36 male, 17 female) and 55 to receive BEAM (39 male, 16 female). All patients engrafted rapidly. Lung toxicity did not differ between groups (BendaEAM: n = 8, 19.5%; BEAM: n = 11, 25.6%; risk difference = -6.1%: 95% confidence interval: -23.9% to 11.7%). Acute toxicities of at least grade 3 were comparable in both groups (BendaEAM: 35.8%, BEAM: 30.9%). Overall survival (BendaEAM: 92.5%, BEAM: 89.1%) and complete remission (BendaEAM: 76.7%, BEAM: 74.3%) after 1 year (median follow-up: 369 days) were similar. No difference in quality of life was observed.

Interpretation

Results were similar for both regimens in terms of survival and response rates. A phase 3 non-inferiority study is required to investigate whether BendaEAM can be considered as an alternative to BEAM.

Funding

Mundipharma.

Single-center retrospective study assessing the efficacy and safety of BeEAM (bendamustine, etoposide, cytarabine, melphalan) as conditioning regimen for autologous hematopoietic stem cell transplantation

One of the most widely accepted conditioning regimens for hematopoietic stem cell transplantation (HSCT) is BEAM (carmustine, etoposide, cytarabine, melphalan). However, a recent increase in the cost of carmustine has limited its use bringing our institution to replace carmustine with bendamustine. This observational retrospective single-center study aims to report the efficacy and safety of the BeEAM regimen. 55 patients with diffuse large B-cell lymphoma (47%), Hodgkin lymphoma (25%), mantle cell lymphoma (25%), or follicular lymphoma (2%) were included. Progression-free survival (PFS) at 24 months was 75% and overall survival (OS) was 83%. Treatment-related mortality was 4%. The most common adverse effects were febrile neutropenia (98%), mucositis (72%) and colitis (60%). Our study demonstrated excellent efficacy of the BeEAM regimen. However, the toxicity profile of BeEAM significantly varies from one study to another, and guidelines suggesting optimal dose of bendamustine and supportive care are currently lacking.

BeEAM (Bendamustine, Etoposide, Cytarabine, Melphalan) Versus BEAM (Carmustine, Etoposide, Cytarabine, Melphalan) as Conditioning Regimen Before Autologous Haematopoietic Cell Transplantation: A Systematic Review and Meta-Analysis

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard of care for selected patients with refractory/relapsed Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL), and it is also used as first-line clinical consolidation option for some aggressive NHL subtypes. Conditioning regimen prior to ASCT is one of the essential factors related with clinical outcomes post transplant. The conditioning regimen of carmustine, etoposide, cytarabine, and melphalan (BEAM) traditionally is considered the standard of care for patients with lymphoma who are eligible for transplantation. Replacement of carmustine with bendamustine (BeEAM) was described as an alternative conditioning regimen in the autograft setting for patients with lymphoma. Several studies have reported inconsistent clinical outcomes comparing BeEAM and BEAM. Therefore, in the lack of well-designed prospective comparative studies, the comparison of BeEAM versus BEAM is based on retrospective trials. To compare the clinical outcomes between BeEAM and BEAM, we performed a meta-analysis of 10 studies which compared the outcomes between BeEAM and BEAM in patients autografted for lymphoma disease (HL or NHL). We searched article titles and compared transplantation with BeEAM versus BEAM in MEDLINE (PubMed), Cochrane library, and EMBASE database. Here, we report the results of nine main endpoints in our meta-analysis comparing BeEAM and BEAM, including neutrophil engraftment (NE), platelet engraftment (PE), overall survival (OS), progression free survival (PFS), non-relapse mortality (NRM), relapse rate (RR), grade 3 mucositis, renal toxicity, and cardiotoxicity. We discovered that the BeEAM regimen was associated with a slightly better PFS [pooled odds ratio (OR) of 0.70, 95% confidence interval (CI), 0.52-0.94, P = 0.02], lower RR (0.49, 95% CI, 0.31-0.76, P = 0.002), higher mucositis (3.43, 95% CI, 2.29-5.16, P = 0.001), renal toxicity (4.49, 95% CI, 2.68-7.51, P = 0.001), and cardiotoxicity (1.88, 95% CI, 1.03-3.40, P = 0.03). We also discovered that the two groups had equivalent NE (pooled WMD -0.64, 95% CI, -1.46 to 0.18, P = 0.13), PE (pooled WMD -0.3, 95% CI, -1.68 to 2.28, P = 0.77), OS (0.73, 95% CI, 0.52-1.01, P = 0.07), and NRM (1.51, 95% CI, 0.76-2.98, P = 0.24). The results of this meta-analysis show that the BeEAM regimen is a viable alternative to BEAM. More prospective comparisons between BeEAM and BEAM are required.