• Kaplan-Meier Estimates for Median Time to Death From Any Cause [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Kaplan-Meier estimates for the median months until death from any cause within the intent-to-treat population. Patients surviving at the end of the follow-up period were censored at the date of last contact. If a patient withdrew consent to follow-up or was lost to follow-up, the patient was censored as of the last date of contact.
  
  
• Summary of Subgroup Analyses for Kaplan-Meier Estimates for Time to Death From Any Cause [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]

  Kaplan-Meier estimates for the median months until death from any cause within the intent-to-treat population. Patients surviving at the end of the follow-up period were censored at the date of last contact. If a patient withdrew consent to follow-up or was lost to follow-up, the patient was censored as of the last date of contact.

  Subgroups that were analyzed are age, gender, French-American-British (FAB) classification, World Health Organization (WHO) classification and International Prognostic Scoring System (IPSS) classification.

  
  
• Number of Participants Who Died [ Time Frame: 42 months ] [ Designated as safety issue: No ]
  Count of participants who died during the study
  
  

• Kaplan-Meier Estimate for Median Time to Transformation to Acute Myeloid Leukemia (AML) or Death From Any Cause, Whichever Occurred First [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  The time to transformation to AML or death from any cause (whichever occurred first) was defined as the number of days from the date of randomization until the date of documented AML transformation or death from any cause. Patients who did not transform to AML or die were censored at the date of last follow-up.
  
  
• Kaplan-Meier Estimates for Median Time to Transformation to Acute Myeloid Leukemia (AML) [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  The time to transformation to AML was defined as the number of days from the date of randomization until the date of documented AML transformation, defined as a bone marrow blast count ≥ 30% independent of baseline bone marrow count. Patients who did not transform to AML were censored at the date of last follow-up or date of death.
  
  
• Summary of Participants' Red Blood Cell (RBC) Transfusion Status for Participants Who Were Transfusion Dependent at Baseline [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Summary of dependence and independence from red blood cell (RBC) transfusion at baseline and during treatment, for patients who were dependent at baseline. A patient was considered transfusion independent at baseline if the patient had no transfusions during the 56 days prior to randomization. During study, a patient was considered transfusion independent during the on-treatment period if the patient had no transfusions during any 56 consecutive days or more. Otherwise, the patient was considered transfusion dependent.
  
  
• Summary of Participants' Red Blood Cell (RBC) Transfusion Status for Participants Who Were Transfusion Independent at Baseline [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Summary of dependence and independence from red blood cell (RBC) transfusion at baseline and during treatment, for patients who were independent at baseline. A patient was considered transfusion independent at baseline if the patient had no transfusions during the 56 days prior to randomization. During study, a patient was considered transfusion independent during the on-treatment period if the patient had no transfusions during any 56 consecutive days or more. Otherwise, the patient was considered transfusion dependent.
  
  
• Summary of Participants' Platelet Transfusion Status for Participants Who Were Transfusion Dependent at Baseline [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Summary of dependence and independence from platelet transfusion at baseline and during treatment for patients who were dependent at baseline. A patient was considered transfusion independent at baseline if the patient had no transfusions during the 56 days prior to randomization. During study, a patient was considered transfusion independent during the on-treatment period if the patient had no transfusions during any 56 consecutive days or more. Otherwise, the patient was considered transfusion dependent.
  
  
• Summary of Participants' Platelet Transfusion Status for Participants Who Were Transfusion Independent at Baseline [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Summary of dependence and independence from platelet transfusion at baseline and during treatment for patients who were independent at baseline. A patient was considered transfusion independent at baseline if the patient had no transfusions during the 56 days prior to randomization. During study, a patient was considered transfusion independent during the on-treatment period if the patient had no transfusions during any 56 consecutive days or more. Otherwise, the patient was considered transfusion dependent.
  
  
• Number of Participants Considered Hematologic Responders by Investigator Determinations Using International Working Group (IWG 2000) Criteria for Myelodysplastic Syndrome (MDS) [ Time Frame: Day 1 to 42 months ] [ Designated as safety issue: No ]

  Investigator determined responses followed IWG criteria for

  • complete remission(CR): repeat bone marrow show <5% myeloblasts, and peripheral blood evaluations lasting >=2 months of hemoglobin(>110 g/L), neutrophils(>=1.5x10^9/L), platelets(>=100x10^9/L), blasts (0%) and no dysplasia
  • partial remission(PR) is the same as CR for peripheral blood: bone marrow shows blasts decrease by >=50% or a less advanced FAB classification from pretreatment
  • stable disease(SD) is a failure to achieve at least a partial remission, but with no evidence of progression for at least 2 months.
  
  
• Number of Participants Showing Hematologic Improvement Using International Working Group (IWG 2000) Criteria for Myelodysplastic Syndrome (MDS) Assessed by Independent Review Committee [ Time Frame: Day 1 to 42 months ] [ Designated as safety issue: No ]

  IWG 2000 Criteria: Pretreatment=hemoglobin <100g/L or RBC transfusion-dependent, platelet count <100x10^9/L or platelet transfusion dependent, absolute neutrophil count <1.5x10^9/L.

  Erythroid response: Major->20g/L increase or transfusion independent. Minor- 10-20g/L increase or >=50% decrease in transfusion requirements.

  Platelet response: Major-absolute increase of >=30x10^9/L or platelet transfusion independence. Minor->=50% increase.

  Neutrophil response: Major->=100% increase or an absolute increase of >0.5x10^9/L. Minor->=100% increase and absolute increase of <0.5x10^9/L.

  
  
• Time to Disease Progression, Relapse After Complete or Partial Remission, or Death From Any Cause [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  The time to disease progression, relapse after complete or partial remission (CR, PR), or death from any cause was defined as the time from the date of randomization until the first date of documented disease progression, relapse after CR or PR, or death from any cause.
  
  
• Duration of Any Hematologic Improvement [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  The duration of improvement was defined as the time from the date of hematologic improvement until the date of first documented progression or relapse after hematologic improvement or death from any cause.
  
  
• Number of Infections Per Treatment Year Requiring Intravenous Antibiotics, Antifungals or Antivirals [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  The on-treatment adverse event rate of infection requiring IV antibiotics, antifungals, or antivirals per patient-years. The on-treatment period was considered the period from the date of randomization to the last treatment study visit.
  
  
• Number of Participants in Different Categories of Adverse Experiences During Core Study Period [ Time Frame: Day 1 (randomization) to 42 months ] [ Designated as safety issue: No ]
  Patient counts for a variety of subsets of adverse experiences for the core study period (day 1 to 42 months). The individual options for Conventional Care Regimens (Best Supportive Care Only, Low-Dose Cytarabine, and Standard Chemotherapy) are presented as separate treatments.
  
  

Comparison/Control Interventions offered the physician three options:

• Best supportive care (BSC) alone,
• Low-dose cytarabine subcutaneously for 14 days every 28 to 42 days, or
• Standard chemotherapy administered for induction as a continuous intravenous infusion of cytarabine over 7 days plus an anthracycline (daunorubicin, idarubicin, or mitoxantrone) on Days 1, 2, and 3; and, for those eligible, 1 or 2 consolidation cycles administered as continuous intravenous infusions of cytarabine for 3 to 7 days with the same anthracycline that was used at induction on Days 1 and 2 (each cycle between 28 to 70 days from the start of the previous cycle).

All three options included best supportive care. Neither the experimental group (azacitidine) nor any of the comparison/control options allowed use of erythropoietin.

Duration of Intervention: Patients will be treated until death, withdrawal, unacceptable toxicity or conclusion of the study.