COMPARISON OF MARROW VS BLOOD-DERIVED STEM-CELLS FOR AUTOGRAFTING IN PREVIOUSLY UNTREATED MULTIPLE-MYELOMA

Sixty-three new untreated patients with multiple myeloma under the age of 70 years received C-VAMP induction treatment followed by high-dose intravenous melphalan (200 mg m(-2)) and autologous stem cell transpl ant, either with marrow [autologous bone marrow transplants (ABMT), n = 26] or with granulocyte colony-stimulating factor (G-CSF)-mobilized stem cells from the blood [peripheral blood stem cell transplants (PBS CT), n = 37]. This was a sequential study and the two groups were not significantly different for all known prognostic variables. The comple te remission (CR) rate after high-dose treatment was the same for both groups [ABMT 84% and PBSCT 70%; P = not significant (NS)]. Neutrophil recovery to 0.5 x 10(9) l(-1) occurred at a median of 22 days in the ABMT patients compared with 19 days for the PBSCT patients (P = NS). P latelet recovery to 50 x 10(9) l(-1) was significantly faster in PBSCT patients (19 days vs 33 days; P = 0.0015), and the PBSCT patients spe nt fewer days in hospital (median 20 vs 27 days; P = 0.00001). There w as no difference in the two groups with respect to starting interferon (58 days for ABMT vs 55 days for PBSCT), and tolerance to interferon was identical. The median overall survival (OS) and progression-free s urvival (PFS) for the PBSCT patients has not yet been reached. The OS in the ABMT patients at 3 years was 76.9% (95% CI 60-93%) compared wit h 85.3% (95% CI 72-99%) in the PBSCT patients (P = NS), and the PFS at 3 years in the ABMT patients was 53.8% (95% CI 34-73%) and in the PBS CT patients was 57.6% (95% CI 34-81%) (P = NS). The probability of rel apse at 3 years was 42.3% in the ABMT arm compared with 40% in the PBS CT patients (P = NS). Thus, PBSCT patients had a faster engraftment an d a shorter stay in hospital than ABMT; the survival outcome and proba bility of relapse was the same for both groups.