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 × 10⁶ to 5 × 10⁶ 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.