Mobilization with chemotherapy (CT) plus hematopoietic growth factors (HGFs) is superior to mobilization with HGFs only. For stem cell mobilization after chemotherapy HGFs are typically given once or twice a day for approximately 14 days. The aim of this study was to evaluate whether mobilization of peripheral blood stem cells (PBSC) with DT-PACE plus pegfilgrastim was equivalent to mobilization with DT-PACE + filgrastim. Patients analyzed were enrolled in two consecutive studies 2001–12 (N=97) and 2003–41 (N=72) and included only patients who had received ≥ 2 cycles of prior therapy, but no prior transplant. Both protocols employed a single cycle of induction with DT-PACE (

Lee et al.
) followed by stem cell collection with either filgrastim 5μg/kg bid until completion of stem cell collection (2001–12) or pegfilgrastim 6mg on days 6 and 13 (2003–41). Patients then proceeded with tandem transplants, one consolidation cycle with DT-PACE and two years of maintenance with thalidomide (100mg daily) and dexamethasone (4 mg/day, days 1–4 q 3 weeks). Group characteristics were compared using the Kruskall-Wallis test. Time to hematopoietic recovery after transplantation was analyzed with Kaplan-Meier plots, and comparison was performed using the logrank statistic. The two studies had comparable characteristics, except that more patients ≥ 65 years were enrolled in 2003–41 (35% vs 13%; p=.001). The median number of collection days was 2 in both studies (p=.8). The median number of CD34 cells/kg (x106) collected per day was 9.7 (2001–12) vs 12.7 (2003–41) (p=.2). The total number of CD34 cell/kg (x106) collected was 20.4 (2001–12) versus 25.4 (2003–41) (p=.2). The median number of CD34 cells/kg (x106) infused after the first transplant was 4.1 (2001–12) and 4.5 (2003–41) (p=.5). The time to recover ANC > 500/μl and platelets > 20,000/μl without transfusion was shorter for 2003–41 patients (13 versus 15 days; p< .0001) (Figure 1). Mobilization of PBSC with pegfilgrastim is easier for patients because they only receive 2 injections and is as effective as filgrastim when combined with DT-PACE. Moreover, mobilization with pegfilgrastim may result in a more rapid hematologic recovery after transplantation.

Cumulative incidence analysis Recovery of ANC to 500 and Platelets > 20K 2003-41 vs. 2001-12, Transplant 1

Cumulative incidence analysis Recovery of ANC to 500 and Platelets > 20K 2003-41 vs. 2001-12, Transplant 1

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