HIGH-DOSE CLADRIBINE THERAPY FOR CHRONIC MYELOGENOUS LEUKEMIA IN THE ACCELERATED OR BLAST PHASE

Purpose: A phase II clinical trial was performed to evaluate the effec tiveness of high-dose cladribine (2CDA) for treatment of chronic myelo genous leukemia (CML) in the accelerated or blast phase, Patients and Methods: Nineteen patients were treated, The median age was 55 years ( range, 30 to 73), Six were older than 60 years, Eight had progressed a fter intensive combination chemotherapy and three after allogeneic or autologous transplantation. For the first course, 16 patients received 2CDA at 15 mg/m(2)/d intravenously (IV) over 1 hour for 5 days, Two r eceived 18 mg/m(2) and one received 21.5 mg/m(2) daily, The second cou rse was escalated to 20 mg/m(2)/d in five patients, Results: Rapid cyt oreduction of leukemia occurred in the blood, with the nadir at 10 to 12 days, The median WBC count decreased from 36,900/mu L before treatm ent to 500/mu L at the nadir and recovered to 5,200/mu L at day 30, Th e median platelet count changed from 113,000/mu L to 24,000/mu L at th e nadir and 71,000/mu L at day 30, The complete remission (CR) plus pa rtial remission (PR) rate was 47% (95% confidence interval [CI], 23% t o 72%), One 64-year-old man with lymphoid blast phase of CML had a mor phologic and cytogenetic CR that lasted 9 months, The median survival for all patients was 34 weeks, and the median survival for the eight r esponders was 56 weeks (range, 11 to 167), The median number of days s pent in hospital over the entire treatment period was 19 (range, 4 to 60), Conclusion: High-dose 2CDA therapy provides effective palliation for CML in accelerated or blast phases, even for heavily pretreated pa tients. (C) 1998 by American Society of Clinical Oncology.