Induction Regimen May Be Effective for Primary Plasma Cell Leukemia
Induction with bortezomib and dexamethasone plus doxorubicin or cyclophosphamide induces high response rates.
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.