A Phase III Study of Dasatinib vs Imatinib in Patients With Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia

Percentage of Participants Remaining in Confirmed Complete Cytogenetic Response (cCCyR)

Cytogenetic response (CyR) is based on the prevalence of Philadelphia positive (Ph+) cells in metaphase from bone marrow (BM) sample. (Ideally, 25 metaphases but at least 20 metaphases from a BM sample were evaluated). Complete Cytogenetic Response (CCyR)=0% Ph+ cells in metaphase in BM. A cCCyR=those in which all measurements up to at least 28 days after the initial response show an equivalent or better CCyR. Percentage of participants in cCCyR at years 2, 3, 4 and 5 was computed for all randomized participants who achieved cCCyR as measured from the time of first confirmation until the date of progression or death. Participants with cCCyR who neither progress nor die are censored on the date of their last cytogenetic assessment. Participants without cCCyR are considered to have progressed on Day 1.

Time frame: Years 2, 3, 4 and 5

Percentage of Participants With Major Molecular Response (MMR) at Any Time

Molecular response was assessed using BCR-ABL transcript levels measured by realtime quantitative polymerase chain reaction. MMR is defined as a ratio BCR-ABL/ABL ≤0.1% on the international scale (ie, at least 3 log reduction from a standardized baseline value).

Time frame: Planned total follow-up duration of 5 years

Time to Confirmed Complete Cytogenic Response (cCCyR) Overall

The time to cCCyR for all randomized participants is defined as the time from the randomization date until criteria are first met for complete cytogenic response (provided it is confirmed later). The time to cCCyR analysis censors nonresponders who do not progress at their last cytogenetic assessments and nonresponders who progress at the maximum time of all randomized participants. .