Steady-state cd34+ cell mobilization with g-csf in patients with chemosensit1ve, pretreated multiple myeloma
Objective: To investigate the feasibility of mobilizing peripheral CD34+ blood cell with G-CSF atone in patients with pretreated multiple myeloma. Methods: 18 patients (8 male/10 female), median age 53 years (range 37-59) with multiple myeloma either in first remission (n=5) or with chemosensitive relapse (n=13) were mobilized with G-CSF 10/ug/kg/BW (n=15) or 24 ug/kg/BW (n=4) given daily on 5 consecutive days. PBSC were harvested on day 5, 6 and 7 after beginning of G-CSF-administration. The minimum of CD34+ cells required was 2.5 x 10s kg/BW. The chemotherapypretreatment consisted of a median number of 6.5 cycles (range 4 18). Results: After a median of 3 leukaphereses (range 1-4) a median of 3,9 x 10(range 2,26-32,3) CD34+ cells /Kg/BW was harvested. Only one Pt who was pretreated with 14 cycles of melphalan and stimulated with lOjjg/kg/BW G-CSF did not reach sufficient CD34+cells (2,26 x 10CD34+ Kg/BW) and a subsequent stimulation with 24ug/kg/BW G-CSF was performed resulting in a CD34+ cell count of 3,22 x 10/Kg/BW. In contrast a patient with insufficient CD34+ cells following mobilization with 4g Cyclophosphamide plus Spg/Kg/BW G-CSF (1,2 x10kg/BW) was stimulated with 24ug/kg/BW G-CSF alone resulting in a sufficient CD34+ cell count (2,5 x 10/kg/BW). Pts pretreated with a median of 6 cycles of melphalan (range 1-14) (n=12) had a significant lower median amount of CD34+ cell (2,89x10Kg/BW range 2,26-5,33), compared to pts (n=6) who were pretreated with VAD- or Cyclophosphamide-based regimens ( median number of cycles:4, range 4-8)(median CD34+ count: 9,84 x 10Kg/BW, range: 3,2232,9) (p=0.02). Conclusions: G-CSF atone is effective to collect PBSC with sufficient number of CD34+ cells with a possible doseresponse effect even In highly pretreated pts with multiple myeloma. Pretreatment with melphalan had an adverse effect on the amount of CD34+ cells and should be avoided if high-dose chemotherapy is planned.