A prospective randomized study of alpha-2b interferon plus hydroxyurea or cytarabine for patients with early chronic phase chronic myelogenous leukemia: The International Oncology Study Group CML1 study

A prospective randomized international study of 143 patients showed no appa rent early survival advantage conferred by combining cytarabine, rather tha n hydroxyurea, with INF as first-line CML therapy. Combinations of alpha-interferon IIND and chemotherapeutic agents are curre ntly first-line therapy for the majority of patients with chronic myeloid l eukemia (CML). The International Oncology Study Group conducted a prospecti ve randomized study comparing INF combined with hydroxyurea or cytarabine. The primary study aim was to compare the survival durations in these patien t cohorts. Patients with early chronic phase CML were randomized to receive INF 5 million units (Mu) given five times per week subcutaneously plus hyd roxyurea or cytarabine as required to achieve a complete hematologic respon se and to maintain a WBC count between 2x10(9)/L and 10x10(9)/L, and a plat elet count between 75x10(9)/L and 100x10(9)/L. Therapy continued as tolerat ed unless progressive or blast phase disease occurred. At 36 months. the ac tuarial survival rate was equivalent in both groups: HI group (79 patients) survival was 85% (95% CI, 68-100%), as compared to 95% (95% CI, 79-100%) i n the CI group (64 patients). In conclusion if seems that there is no appar ent early survival advantage conferred by combining cytarabine, rather than hydroxyurea, with INF as first-line CML therapy.