Design and first interim analysis of a randomized phase III trial comparing imatinib versus imatinib (IM) based combination therapies in newly diagnosed chronic myelogenous leukemia patients in chronic phase

6589 Background: Despite impressive results achieved with IM 400 mg/day alone, only a minority of pts reached a complete molecular remission at 12-month. Higher dose of IM or its combination with other therapies might improve molecular remission. Design of the trial: the 3 experimental arms are IM 400mg daily in combination with Peg-IFN-α2a (Peg-IFNα2a, 90 μg weekly) or with Ara-C (20 mg/m2/day, days 15–28 of 28-day cycles) or IM 600mg daily. The reference arm is IM 400mg daily. All pts (over 18 years of age with Bcr-Abl positive CML) receive IM 400 mg/day as monotherapy days 1–14 and then start the assigned regimen for at least 12 months. The endpoints are overall survival (primary), rate and duration of hematologic, cytogenetic and molecular responses and tolerability. An interim analysis of the first 636 pts at 1 year from randomization will allow evaluation of molecular response rates, one of the experimental arm being selected for further comparison with IM 400. An experimental arm would be selected ...