Induction with bortezomib and dexamethasone plus doxorubicin or cyclophosphamide followed by autologous hematopoietic cell transplantation (HCT) induces high response rates and may significantly improve progression-free survival in patients with primary plasma cell leukemia (pPCL), a study published in the Journal of Clinical Oncology has shown.1
pPCL is a rare and aggressive malignancy that carries a poor prognosis; even with conventional chemotherapy, patients typically die within 1 year. Therefore, researchers sought to evaluate the efficacy of a regimen that combines standard chemotherapy, a proteasome inhibitor, high-dose melphalan, and autologous HCT, followed by either allogeneic HCT or maintenance therapy with bortezomib and lenalidomide.
For the phase 2 trial, researchers enrolled 40 patients aged 70 years and younger with newly diagnosed pPCL. Participants received 4 alternating cycles of bortezomib and dexamethasone plus doxorubicin or cyclophosphamide. Responding patients underwent high-dose melphalan and autologous HCT.
Young patients then received a reduced-intensity conditioning allograft, while older patients underwent a second round of high-dose melphalan and autologous HCT, followed by bortezomib, lenalidomide, and dexamethasone for 1 year.
Results showed that at a median follow-up of 28.7 months, median progression-free survival was 15.1 months (95% CI, 8.4-not reached). Median overall survival was 36.3 months (95% CI, 25.6-not reached).
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Researchers also found that the overall response rate to induction therapy was 69%. Of those, 1 patient underwent a syngeneic allograft and 25 received high-dose melphalan and autologous HCT. Of those 25 patients, 16 subsequently received a reduced-intensity conditioning allograft and 7 patients underwent a second autologous HCT followed by maintenance chemotherapy.
- Royer B, Minvielle S, Diouf M, et al. Bortezomib, doxorubicin, cyclophosphamide, dexamethasone induction followed by stem cell transplantation for primary plasma cell leukemia: a prospective phase II study of the Intergroupe Francophone du Myélome [published online ahead of print April 25, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.63.1929.