Intensive chemotherapy induction followed by interferon-alpha maintenance in patients with Philadelphia chromosome-positive chronic myelogenous leukemia.

In a pilot study, 32 patients with Philadelphia chromosome-positive chronic myelogenous leukemia were treated with intensive chemotherapy induction followed by interferon-alpha (IFN-A) maintenance. Intensive chemotherapy consisted of three cycles of daunorubicin 120 mg/m2 on day 1, cytarabine 80 mg/m2 daily for 10 days, vincristine 2 mg on day 1, and prednisone 100 mg daily for 5 days (DOAP). Maintenance therapy with IFN-A at a doses of 3 x 10(6) to 5 x 10(6) units/m2 daily was adjusted according to counts and toxicity. The outcome of patients was compared with a matched historic population of 64 patients treated with IFN-A alone. Overall, 60% of patients had a cytogenetic response (partial or complete) with induction chemotherapy, but only eight (25%) had a sustained cytogenetic response with IFN-A maintenance. After a median follow-up of 67 months, the 6-year survival rate of the 32 patients was 58%, compared with 36% for the matched historic group (P = 0.084). The incidence of lymphoid blastic transformation in the two groups was 25% and 48%, respectively (P = 0.10) and durable cytogenetic responses, 25% and 19%, respectively (P = 0.48). In summary, the addition of intensive chemotherapy induction to IFN-A maintenance does not improve the survival rate, incidence of lymphoid blastic transformation, or incidence of durable cytogenetic response compared with the results achieved with IFN-A therapy alone.