Efficacy and safety of the BEBM (bendamustine, etoposide, busulfan, and melphalan) conditioning regimen for autologous stem-cell transplantation in non-Hodgkin lymphoma.

BACKGROUND

Bendamustine, etoposide, and busulfan (BEB) is a conditioning regimen used for autologous stem-cell transplantation (ASCT) in non-Hodgkin lymphoma (NHL). We investigated whether addition of melphalan (BEBM) could enhance this regimen.

METHODS

BEBM with melphalan at 50, 70, or 100 mg/m2 was assessed in 12 high-risk or relapsed/refractory NHL patients (10 in complete response before ASCT) in a phase I 3 + 3 dose-escalation study. The primary endpoint was dose-limiting toxicity (DLT).

RESULTS

All patients experienced grade ≥ 3 hematologic toxicities. Cohort 1 (50 mg/m2) exhibited no grade ≥ 3 non-hematologic adverse events (AEs). Cohort 2 (70 mg/m2, n = 6) exhibited two DLTs (grade 4 mucositis; one sepsis-related death). Cohort 3 (100 mg/m2, n = 1) was prematurely terminated and had no severe non-hematologic AEs. The 3-month complete response rate was 90.9%. At a median follow-up of 57.5 months, progression-free survival and overall survival rates were 58.3 and 66.7%.

CONCLUSION

BEBM demonstrated an acceptable safety profile, although significant toxicities were observed at 70 mg/m2. While preliminary efficacy outcomes were encouraging, their interpretation is limited by the phase I design, small sample size, and premature termination of the highest-dose cohort. Larger prospective studies are warranted to further define the safety profile and evaluate the therapeutic potential.