Safety and Efficacy of Imatinib Versus Interferon-α Plus Cytarabine in Patients With Newly Diagnosed Philadelphia Chromosome Positive Chronic Myelogenous Leukemia

Overall survival was defined as the time between date of randomization and death due to any cause. The time was censored at last examination date for patients who were still being treated and at date of last contact for patients who discontinued treatment. Kaplan-Meier estimates of the percentage of participants at each time point was calculated. This outcome was measured in all randomized patients, regardless of whether crossover occurred, i.e., events that occurred in patients, who had crossed over, were attributed following crossover to the original randomized treatment.

Event-free survival is defined as the time between randomization and the earliest of any of the following events on treatment:

• progression to Accelerated Phase (AP) or Blast Crisis (BC)
• loss of Complete Hematological Response (CHR)
• loss of Major Cytogenetic Response (MCyR) confirmed
• loss of Major Cytogenetic Response (MCyR) unconfirmed
• increase in white blood cell count (WBC) if approved by the Study Management Committee (SMC)
• death (due to any cause when reported as primary reason for discontinuation of treatment).

Kaplan Meier estimates of the percentage of participants with Event Free Survival at the given time point was calculated. This outcome was measured in all randomized patients, regardless of whether crossover occurred, i.e., events that occurred in patients, who had crossed over, were attributed following crossover to the original randomized treatment.

Event-free survival is defined as the time between randomization and the earliest of any of the following events on treatment:

• progression to Accelerated Phase (AP) or Blast Crisis (BC)
• loss of Complete Hematological Response (CHR)
• loss of Major Cytogenic Response (MCyR) confirmed
• loss of Major Cytogenic Response (MCyR) unconfirmed
• increase in white blood cell count (WBC) if approved by the Study Management Committee (SMC)
• death (due to any cause when reported as primary reason for discontinuation of treatment).

The percentage of participants with Event Free Survival events in each category was calculated. This outcome was measured in all randomized patients, regardless of whether crossover occurred, i.e., events that occurred in patients, who had crossed over, were attributed following crossover to the original randomized treatment.

Time to progression to AP/BC is defined as the time between randomization and either of the following events on treatment: death (due to CML when reported as primary reason for discontinuation of treatment) or progression to Accelerated Phase or Blast Crisis and is censored at last examination date for patients without event. No data after discontinuation of study treatment was included. The Kaplan Meier estimates of the percentage of participants with survival without progression to AP/BC at the given time point was calculated. This outcome was measured in all randomized patients, regardless of whether crossover occurred, i.e., events that occurred in patients, who had crossed over, were attributed following crossover to the original randomized treatment.

Bone marrow aspirate was performed to evaluate cytogenetic results (percentage of Philadelphia chromosome positive (Ph+) metaphases) and amount of blasts and promyelocytes in bone marrow to establish cytogenetic response.

Major Cytogenetic Response= Complete Response or Partial Response. Complete Cytogenetic Response= 0 % of Ph+ metaphases (out of 20 metaphases). Partial Cytogenetic Response= > 0 and ≤ 35 % of Ph+ metaphases (out of 20 metaphases). The percentage of participants with cytogenetic response in each category was calculated.

Bone marrow aspirate was performed to evaluate cytogenetic results (percentage of Ph chromosome (Ph+) containing metaphases) and the amount of blasts and promyelocytes in bone marrow to establish cytogenetic response.

Major Cytogenetic Response= Complete Response or Partial Response. Complete Cytogenetic Response= 0 % of Ph+ metaphases (out of 20 metaphases). Partial Cytogenetic Response= > 0 and ≤ 35 % Ph+ metaphases (out of 20 metaphases). The percentage of participants with cytogenetic response in each category was calculated.

A serious adverse event is any experience that suggests a significant hazard, contraindication, side effect or precaution that: results in death, is life-threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect or is medically significant

A serious adverse event is any experience that suggests a significant hazard, contraindication, side effect or precaution that: results in death, is life-threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect or is medically significant

Major Molecular Response was determined using a quantitative polymerase chain reaction (PCR) laboratory test and was defined as BCR-ABL protein transcripts of ≤ 0.1% according to the international scale.

Major Molecular Response was determined using a quantitative polymerase chain reaction (PCR) laboratory test and was defined as BCR-ABL protein transcripts of ≤ 0.1% according to the international scale.