High-dose Hydroxyurea and G-CSF to Collect Philadelphia-Negative Cells in Chronic Myeloid Leukemia: Preliminary Results

Five patients with Ph+ chronic myeloid leukemia and no detectable diploid cells in the marrow received 6 g hydroxyurea twice daily for 7 days followed by G-CSF to harvest Ph- cells 1-84 months after diagnosis. Three were in first chronic phase, and two in accelerated phase. One stopped hydroxyurea after 4 doses due to intractable vomiting and was not apheresed, while two stopped hydroxyurea after 9 and 11 doses because of mucositis and skin rash. Two tolerated all doses; one with no significant side effects, and one with mucositis and painful plantar rash. The nadir leukocyte, neutrophil, and platelet counts were 0.4-0.8, 0-0.1, and 2-19 × 109/L respectively. Apheresis was commenced when the leukocytes were 1.2-3.8 × 109/L 9-10 days after starting G-CSF, and 6 aphereses were performed. Four collections were 100% Ph+, and two 22% and 90% Ph-. The total nucleated cell, CD34+/CD34- subset, CD34+/CD33+ subset, and CFU-GM yields per kg per collection were 0.48-2.38 (median 1.18) × 108, 0-0.48 (median 0.012) × ...