Upfront autologous stem cell transplantation for newly diagnosed elderly multiple myeloma patients: a prospective multicenter study

The feasibility and efficacy of high-dose melphalan followed by autologous hematopoietic stem cell transplantation in newly diagnosed elderly patients with multiple myeloma was analyzed prospectively. Fifty-six multiple myeloma patients, aged 65 years or over, from 6 French centers were studied. The induction therapy was bortezomib-based in combination with dexamethasone and either thalidomide, cyclophosphamide or lenalidomide, for 4-6 cycles. Peripheral blood stem cells were collected after high-dose cyclophosphamide plus G-CSF or G-CSF alone, with plerixafor if needed. The conditioning regimen consisted of melphalan at 140 mg/m² in 18 patients (36%) and 200 mg/m² in 32 (64%). Three months post autologous hematopoietic stem cell transplantation, a 2-month consolidation phase with either lenalidomide plus dexamethasone or bortezomib-based combination therapy was allowed, but maintenance treatment was not given. All but 6 patients underwent autologous hematopoietic stem cell transplantation and 3 had tandem transplantations. The treatment-related mortality was 0% at 100 days post transplantation. Sixty-eight percent received consolidation therapy following transplantation. The best response achieved was 40% complete response, 36% very good partial response, and 18% partial response. After a median follow up of 21 months (range 6-31), the estimated progression-free and overall survival rates at two years were 76% [95%CI: (61.6-94.1)] and 88% [95%CI: (76.7-100)], respectively. The higher dose of melphalan (200 mg/m²) afforded superior progression-free and overall survival rates. This prospective study provides evidence for the safety and efficacy of autologous hematopoietic stem cell transplantation as a first-line treatment approach in elderly multiple myeloma patients. (clinicaltrials.gov identifier: 01671826).