Does high-dose GBM chemotherapy lead to better post-stem cell transplant outcomes compared to BEAM in refractory or relapsed Hodgkin’s lymphoma patients?

This study investigated the outcomes of primary refractory or relapsed Hodgkin’s lymphoma (HL) patients who received GBM (gemcitabine, busulfan, melphalan) or BEAM (carmustine, etoposide, cytarabine, melphalan) chemotherapy before autoSCT (autologous stem cell transplantation). This study concluded that GBM improved patient outcomes compared to the conventional BEAM regimen.

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (autoSCT, using the patient's own stem cells) is the current standard for relapsed or hard-to-treat Hodgkin’s lymphoma (HL). BEAM chemotherapy has remained the standard HDC regimen for autoSCT despite its poor outcomes in primary refractory (cancer does not respond to first-line treatment) or relapsed (cancer returns after first-line treatment) HL. Progression-free survival (PFS; time from treatment before disease progression) rates associated with BEAM are roughly 50%.

Preliminary research with the GBM regimen has shown promising results for hard-to-treat HL. Whether this regimen shows improved outcomes compared to conventional BEAM is under investigation.

This study involved 125 patients with primary refractory (40.8%) or relapsed (59.2%) HL. Patients received either GBM (64%) or BEAM (36%) chemotherapy before stem cell transplantation. PET scanning was done post-chemotherapy and post-transplant. The average follow-up periods were 34.5 months (GBM) and 33 months (BEAM).

The probability of being progression-free at 2 years was 64.8% (GBM) and 49.0% (BEAM). The probability of achieving 2-year overall survival (OS; time from treatment until death from any cause) was 96.3% (GBM) and 69.1% (BEAM). These probabilities were statistically significant.

79% of GBM-treated patients showed an overall response (OR; cancer shrinks or disappears after treatment). 67% of GBM-treated patients showed a complete response (complete disappearance of all signs of cancer). Only 3 out of 5 evaluable BEAM-treated patients showed a CR.

90% (GBM) and 44.4% (BEAM) of patients experienced mild to moderate mouth sores. 32.5% (GBM) and 11.1% (BEAM) of patients experienced mild to moderate skin rash, most of which resolved with ointments. 6.25% (GBM) and 66.7% (BEAM) of patients experienced mild to moderate diarrhea.

42.5% (GBM) and 13.3% (BEAM) of patients also experienced high bilirubin levels in the blood (an indication of liver problems). For GBM patients, this was only in the first week post-transplant. All of these side effects were significantly different between the treatment groups.

This study concluded that GBM improved patient outcomes compared to the conventional BEAM regimen.

The sample size in this study is quite small, and both groups of patients were not randomly assigned. These factors may limit the conclusions that can be drawn. Randomized clinical studies with larger patient populations are needed to confirm these results.

This study was funded by Otsuka Pharmaceuticals, the manufacturer of busulfan.