[Chemotherapy of chronic myelogenous leukemia--VP(M) regimen initiated during its chronic phase, and evaluation of MCNU in the phase of blastic crisis]

Seventy-four patients in the chronic phase of Ph1-positive chronic myelogenous leukemia (CML) have been treated with busulfan or other alkylating agents in a conventional way. During its chronic phase, 24 of these 74 cases had received additional intermittent therapy every 4 to 6 months, consisting of vincristine 2 mg or vindesine 3 mg per week, prednisolone 20-30 mg per day and partly 6 mercaptopurine 50 to 100 mg, combined with allopurinol 200 to 300 mg per day for 2 to 3 weeks. The 50% survival of these patients using the Kaplan-Meier's method was 73.7 months and 5-year survival was 69.6%, against 40.5 months and 14.4%, respectively, in the remaining patients. Nine patients in the blastic or accelerated phase of Ph1-positive CML have been treated with new regimens including MCNU. All cases had been refractory for usual types of induction chemotherapy. The new regimen consisted of MCNU 50-100 mg, combined with vindesine or 6-MP plus allopurinol or prednisolone. Five out of 9 cases attained complete remission and 1 partial remission. The major adverse effect of this regimen was slight liver damage. MCNU could be regarded as an useful agent in the blastic phase as well as in the chronic phase of CML.