Spirit 2: Final 5 Year Analysis of the UK National Cancer Research Institute Randomized Study Comparing Imatinib with Dasatinib in Patients with Newly Diagnosed Chronic Phase CML

▪ Objective. SPIRIT 2 is the largest phase 3 prospective randomized open-label trial comparing imatinib (I) 400mg with dasatinib (D) 100mg daily in newly diagnosed chronic phase CML. The primary endpoint was 5 year event-free survival. Methods. 812 (406 in each arm) of 814 patients recruited started study medication (median age 53.2, 275/812 (33.8%) were over 60 years old). Patients were recruited at 144 hospitals between August 2008 and March 2013 and randomized to receive either imatinib 400mg or dasatinib 100mg daily. Secondary endpoints included overall survival, rates of treatment failure, cytogenetic/molecular response - RT-PCR BCR-ABL/ABL ratio of