Successful Harvesting of Peripheral Hematopoietic Stem Cells after Induction Treatment with Bortezomib, Adriamycin, Dexamethasone (PAD) in Patients with Newly Diagnosed Multiple Myeloma (MM)

Abstract

The HOVON-65/GMMG-HD4 trial is a prospective, randomized phase III trial to evaluate the efficacy of bortezomib prior to high-dose melphalan (200 mg/m2, HDM) on response and progression-free survival (PFS) in patients with newly diagnosed MM stage II or III according to Salmon & Durie (SD). Until May 2008 in total 833 patients aged 18–65 years were included in the trial. Patients were randomized to receive three cycles of VAD (arm A; vincristin 0,4mg, days 1–4, adriamycin 9 mg/m2, days 1–4, dexamethasone 40 mg, days 1–4, 9–12, and 17–20) or PAD (arm B; bortezomib 1.3 mg/m2, days 1,4,8,11, adriamycin 9 mg/m2, days 1–4, dexamethasone 40 mg, days 1–4, 9–12, and 17–20). Hematopoietic stem cells were mobilized in patients using the CAD regimen (cyclophosphamide 1000 mg/m2 iv day 1, adriamycin 15mg/m2, days 1–4, dexamethasone 40mg, days 1–4) and G-CSF. After stem cell harvesting all patients received one or two cycles of HDM with autologous stem cell transplantation followed by maintenance therapy with thalidomide 50 mg daily (arm A) and bortezomib 1.3 mg/m2 once every 2 weeks (arm B), respectively.As of August 2008 stem cell harvesting data from the first consecutively enrolled 150 patients (75 per arm) were analyzed. The data of the initial 300 patients (150 per arm) will be available by November 2008. Both treatment arms did not differ in age, SD stage of disease, ISS stage, and FISH abnormalities. 132 patients (88%) were treated with CAD plus G-CSF. Dosing and type of G-CSF treatment were comparable in both arms.In all patients stem cell collection was successful and at least two autografts could be harvested (minimal number of stem cells permitted per autograft was 2.0 ×106 CD 34+ cells per kg BW).Induction treatmentDays until first leukapheresis Median (range)Number of leukaphereses Median (range)Number of harvested CD34+ stem cells (× 106) per kg BW Median (range)PAD110 (96–149)1 (1–4)10.5 (4.1–37.6)VAD111 (95–156)1 (1–5)9.3 (4.0–37.0)In 64% of the patients in arm A (VAD) and 79% of the patients in arm B (PAD) only one leukapheresis was sufficient for stem cell harvesting. In all patients hematopoietic reconstitution was achieved after HDM followed by autografts harvested after PAD or VAD. We conclude that stem cell harvesting after PAD is very well feasible.