Mobilization strategies for the collection of peripheral blood progenitor cells: Results from a pilot study of delayed addition G-CSF following chemotherapy and review of the literature

Objective

Given the potential to limit cost, we conducted a pilot study evaluating delayed, low-dose granulocyte colony-stimulating factor (G-CSF) following chemotherapy for the procurement of peripheral blood progenitor cells (PBPCs) for autologous transplantation and reviewed the relevant literature.

Patients and methods

Twenty-eight patients with various malignancies received cyclophosphamide 4 gm/m² and paclitaxel 170 mg/m² followed by G-CSF 300 μg/d or 480 μg/d starting day +5 until two to four daily large volume leukapheresis yielded ≥5.0 × 10⁶ CD34⁺ cells. We searched MEDLINE, Pubmed, and EMBASE databases from 1990 to the present to identify papers on PBPC procurement using delayed G-CSF (starting day +4 or later) following chemotherapy.

Results

G-CSF was administered for a median of 9 days at an average cost of $1260 USD per 70-kg patient. Collection was initiated at a median of 12 days after chemotherapy. A median 2.5 (range 2–4) apheresis were performed yielding an average daily CD34⁺ collection of 6.9 × 10⁶ /kg (range 0.35–56.7). After one apheresis, 82% and 57% of patients collected ≥2.5 × 10⁶/kg and ≥5.0 × 10⁶/kg, respectively. Ultimately, 89% collected ≥5.0 × 10⁶/kg. Febrile neutropenia and catheter-related infection developed in five and two patients, respectively. All patients proceeded to transplantation and engrafted successfully with a median of 14.9 × 10⁶/kg (range 1.05–113) cells infused. Eleven published reports were identified involving 590 patients of whom 498 received G-CSF at a dose range of 250 μg/d to 10 μg/kg/d starting day +4 to 15 for a period of 4 to 9 days for PBPC procurement. Among these reports, 62 to 100% and 33 to 96% of patients collected ≥2 to 2.5 × 10⁶ and ≥5.0 × 10⁶ CD34⁺ cells, respectively.

Conclusion

The use of delayed, low-dose G-CSF plus chemotherapy for stem cell mobilization was feasible and provides further evidence supporting this potentially cost-effective strategy. A review of the literature supports our findings and emphasizes the need for larger studies to address this issue.