Evaluation of Pegfilgrastim Efficacy in Peripheral Blood Stem Cell Mobilization of Patients with Lymphoma

Twenty four patients (pts) with planned autologous stem cell transplantation for lymphoma diseases (Hodgkin’s disease=4; non-Hodgkin’s lymphoma=20) received chemotherapy (CT) (Induction CT=3 and salvage regimen= 21) followed by a fixed single dose (6 mg) administration of Pegfilgrastim (PF) after the last day of CT for peripheral blood stem cell collection (PBSC) (target cell dose of ³ 2×106 CD34+/kg). Median age was 53 yrs (24–68) and median weight was 72, 5 kg (45–98). Among the 24 pts, 7 received more than 2 lines of CT regimens. The injection of PF was well tolerated. Median time interval between day 1(D1) of the cycle of CT mobilization and first leukapheresis session was 14 days (10–18) while the median time interval between injection of PF and first leukapheresis session was 9 days (6–13). Stem cell collection was started when the absolute number of circulating CD34+ cells was >10×106/L and performed with standard volume leukapheresis. Median CD34+ cells level at D1 of leukapheresis was 35, 5/mm3 (11–320) and interestingly, more than 35 % of pts could reach this median level of CD34+ early after PF injection (around D6). Notably, 22 pts reached the target cell dose in 2 sessions of leukapheresis or less (10 pts after 1 session, 10 other pts after 2 sessions, 2 pts after 3 and 4 sessions respectively). The median number of leukapheresis sessions was 2(1–4) and the median CD34+ cells harvested was 4×106/kg (0,8–26,6). Two pts (DLBCL = 1 and FL = 1) could not reach the level of CD34+ required to start leukapheresis and both became secondary refractory to CT. In univariate analysis, PBSC collection of > 4×10⁶/kg was highly correlated with pts who started their collection at D9 of PF administration (P=0,01) and with those presenting a CD34+ cells level > 35.5/mm³ at D1 of leukapheresis (P=0,033). White blood cells level higher than 9 G/l was also predictive of circulating CD34+ cells >35,5/mm3 (P=0,033). These data suggest that PF may represent an attractive option for PBSC mobilization particularly for pts with lymphoma when optimal compliance of frequent sequential regimens of CT is required. We also emphasize that stem cell mobilization is effective even in pts in second or subsequent salvage CT regimen. Importantly, the circulating CD34+ count should be performed from D6 of PF administration. The presentation will include the updated data.