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

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.

Time frame: Pretreatment, every 3 months up to 12 months

Population: All randomized participants

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

Population: All randomized participants who achieved cCCyR

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

Population: All randomized participants

OS was defined as the time from randomization to the date of death. If the participant had not died, survival was censored on last date the participant was known to be alive.

Time frame: Participants were followed-up for at least 5 years

Population: All randomized participants

PFS was defined as the time from randomization until progression (any progression/death within 30 days of last dosing date, or between 30-60 days of last dosing prior to start of secondary therapy). Those who did not progress/die or who progressed/died after 60 days of last dose were censored at last on-study hematologic/cytogenetic assessment; those with progression/death 30-60 days of last dosing date and after start date of secondary therapy censored at last on-study hematologic/cytogenetic assessment prior to start of secondary therapy; those who had not received study treatment censored on date randomized.

Time frame: Participants were followed-up for at least 5 years

Population: All randomized participants

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. .

Time frame: Day 1 to 5 years

Population: All randomized participants who achieved cCCyR

The time to MMR for all randomized participants is defined as the time from randomization date until measurement criteria are first met for MMR. The time to MMR analysis censors nonresponders who do not progress at their last molecular assessments and nonresponders who progress at the maximum time of all randomized participants.

Time frame: Day 1 to 5 years

Population: All participants who received treatment and achieved MMR

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition in a subject administered an investigational (medicinal) product and that does not necessarily have a causal relationship with this treatment. SAE=any untoward medical occurrence that at any dose results in death, is life-threatening, requires inpatient hospitalization or causes prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event.

Time frame: From date of last person, first visit to date of last person, last visit (approximately 8 years)

Population: All treated participants

ULN=upper limit of normal. Grade 3=Severe AE; Grade 4=Life-threatening or disabling AE. Absolute neutrophil count: Grade 3 \<1000-500/mm\^3; Grade 4 \<500/mm\^3. Hemoglobin: Grade 3 \<8.0-6.5 g/dL; Grade 4 \<6.5 g/dL. Platelets: Grade 3 \<50,000-25,000/mm\^3; Grade 4 \<25,000/mm\^3. ALT/AST: Grade 3 \>5.0-20\*ULN; Grade 4 \>20\*ULN. Total bilirubin: Grade 3 \>3-10\*ULN; Grade 4 \>10\*ULN. Sample normal ranges (may vary by institution): ALT, Female: 7-30 U/L, Male: 10-55 U/L; AST, Female: 9-25 U/L, Male10-40 U/L; Total bilirubin: 0.0-1.0 mg/dL. Creatinine: Grade 3 \>3.0-6.0\*ULN; Grade 4 \>6.0\*ULN. Phosphate: Grade 3 \<2.0-1.0 mg/dL; Grade 4 \<1.0 mg/dL. Calcium: Grade 3 \<7.0-6.0 mg/dL; Grade 4 \<6.0 mg/dL. Potassium: Grade 3 \<3.0-2.5 mmol/L; Grade 4 \<2.5 mmol/L.

Time frame: From date of last person, first visit to date of last person, last visit (approximately 8 years)

Population: Participants with laboratory assessments