MOBILIZATION OF PERIPHERAL STEM-CELLS WITH INTENSIVE CHEMOTHERAPY (ICE REGIMEN) AND G-CSF IN CHRONIC MYELOID-LEUKEMIA

Seventeen patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) were treated with the ICE regimen plus G-CSF wi th the aim of mobilizing and collecting Ph-negative peripheral stem ce lls (PSC) in the setting of an autotransplant program, Fifteen patient s had CR IL in first chronic phase (CP), and two in accelerated phase (AP), Three patients had been previously treated with interferon alpha 2a (IFN), Twelve patients underwent leukaphereses and a mean of 4.7 x 10(8)/kg mononuclear cells were obtained, Four CP patients did not sh ow a significant mobilization peak of CD34(+) cells and leukapheresis was not performed; finally, one patient died before apheresis could be performed, Six of the 12 who underwent leukaphereses obtained more th an 1.0 x 10(6)/kg CD34(+) cells, Eight of the 12 mobilized patients (6 7%) obtained a major cytogenetic response, including two complete and sis partial; in the remaining four patients minimal or absent cytogene tic responses were observed, A higher rate of Ph purging was obtained in patients mobilized early or showing residual Ph-negative cells befo re mobilization, even if they mere in AP. Infectious complications wer e frequent with a 38% rate of bacteremia recorded and one case of pulm onary aspergillosis resulting in a toxicity similar to that occurring in acute myeloid leukemia-induction chemotherapy. The ICE regimen can promote 'in vivo' purging of the Ph+ cells in 67% of CML mobilized pat ients (8/12), Failure of mobilization occurs in 65% of patients (11/17 ), mainly because of poor CD34(+) cell yield.