Early Toxicity and Efficacy of Four Different Conditioning Regimens for Autologous Hematopoietic Cell Transplantation in Patients With Lymphoma: Impact of Drug Shortages in a Resource-Constrained Country

High-dose therapy followed by autologous hematopoietic cell transplant (AHCT) remains a viable consolidation strategy for a subset of patients with relapsed or refractory (R/R) lymphomas. BEAM (carmustine, etoposide, cytarabine, and melphalan) is widely recognized as the predominant conditioning regimen due to its satisfactory efficacy and tolerability. Nevertheless, shortages of carmustine and melphalan have compelled clinicians to explore alternative conditioning regimens. The aim of this study was to compare the toxicity and transplant outcomes following BEAM, CBV (carmustine, etoposide, cyclophosphamide), BuMel (busulfan, melphalan), and BendaEAM (bendamustine, etoposide, cytarabine, melphalan). We retrospectively analyzed data from 213 patients (CBV 65, BuMel 42, BEAM 68, BendaEAM 38) with R/R lymphomas undergoing AHCT between 2014 and 2020. Multivariate models were employed to evaluate toxicity and transplant outcomes based on conditioning type. Among grade III to IV toxicities, oral mucositis was more frequently observed with BuMel (45%) and BendaEAM (24%) compared to BEAM (15%) and CVB (6%, P ≤ .001). Diarrhea was more common with BendaEAM (42%) and less frequent with BuMel (7%, P = .01). Acute kidney injury was only found after BendaEAM (11%). Febrile neutropenia and infectious complications were more frequent following BendaEAM. Frequencies of other treatment-related toxicities did not significantly differ according to conditioning type. BendaEAM (odds ratio [OR] 3.07, P = .014) and BuMel (OR 4.27, P = .002) were independently associated with higher grade III to IV toxicity up to D+100. However, there were no significant differences in relapse/progression, nonrelapse mortality, progression-free survival, or overall survival among the four regimens. BuMel and BendaEAM were associated with a higher rate of grade III to IV toxicity. Carmustine-based regimens appeared to be less toxic and safer; however, there were no significant differences in transplant outcomes. The utilization of alternative preparative regimens due to drug shortages may potentially lead to increased toxicity after AHCT for lymphoma.