The Early Referral for Reduced-Intensity Stem Cell Transplantation in Patients with Ph1 (+) Chronic Myelogenous Leukemia in Chronic Phase in the Imatinib Era: Results of the Latin American Cooperative Oncohematology Group (LACOHG) Prospective, Multicenter Study.

Using a reduced intensity stem cell transplantation (RIST) schedule, 24 patients with Ph1 (+) chronic myelogenous leukemia (CML) in first chronic phase were prospectively allografted in four Latin American countries: Mexico, Brasil, Colombia and Venezuela, using HLA-identical siblings as donors. Median age of the patients was 41 years (range 10 to 71); there were 8 females. Patients received a median of 4.4 x 10⁶/ Kg CD34 cells. Median time to achieve above 0.5 x 10⁹/L granulocytes was 12 days, range 0–41, whereas median time to achieve above 20 x 10⁹/L platelets was also 12 days, range 0–45. Twenty two patients are alive 81 to 830 (median 497) days after the RIST. The 830-day probability of survival is 92%, whereas median survival has not been reached, being above 830 days. Eleven patients (46%) developed acute graft versus-host disease (GVHD), whereas 7 of 23 (30%) developed chronic GVHD. Two patients died 43 and 210 days after the RIST, one as a result of sepsis and the other one of chronic GVHD. The 100-day mortality was 4.4 %, whereas the transplant-related mortality was 8%. RIST for patients with CML in chronic phase seems as an adequate therapeutic option.