The distribution of overall survival was estimated by the method of Kaplan and Meier. A log-rank analysis stratified by randomization stratification factors was used to compare overall survival between Arm A (decitabine/sapacitabine) versus Arm C (decitabine). Cox proportional hazards models were used to identify predictive factors for overall survival.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Normalization of peripheral neutrophils to >=1000 /microliter, platelet to >=100,000/microliter within 2 weeks of bone marrow biopsy/aspirate, and bone marrow to <=5 % blasts; independent of transfusions*; and no extramedullary leukemia.

* independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Normalization of bone marrow to <=5% blasts; peripheral neutrophils >=1000 /microliter, platelet <=100,000 /microliter within 2 weeks of bone marrow biopsy/aspirate; independent of transfusions*; and no extramedullary leukemia.

*independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Normalization of peripheral neutrophils to >=1000 /microliter, platelet to >=100,000/microliter within 2 weeks of bone marrow biopsy/aspirate, >=50% decrease in bone marrow blasts over pre-treatment but still >5%; independent of transfusions*

*independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

HI with duration (HI)

1. Erythroid response (HI-E) for patients with pre-treatment hemoglobin < 11 g/dL; Major response: >2 g/dL increase in hemoglobin; for RBC, transfusion independence* Minor response: 1 to 2 g/dL increase in hemoglobin; for RBC, a 50% decrease in transfusion requirements

2. Platelet response (HI-P) for pre-treatment platelet count <100,000/mm3; Major response: an absolute increase of platelet count by >=30,000/mm3; stabilization of platelet counts and platelet transfusion independence* Minor response: >=50% increase in platelet count with a net increase > 10,000/mm3 but <30,000/mm3

3. Neutrophil response (HI-N) for absolute neutrophil count (ANC) < 1,500/mm3 before therapy; Major response: >=100% increase, or an absolute increase of >500/mm3, whichever is greater Minor response: >=100% increase, but absolute increase < 500/mm3

   • independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Failure to achieve at least hematologic improvement (HI), but no evidence of clinically significant progression for > 16 weeks.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Number of units of packed red blood cells (PRBC) and/or platelet transfusions administered per 8-week period prior to the first dose of study drug and through the date of treatment discontinuation.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

In-patient days in hospital.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

One-year survival is the percentage of patients who are alive at 1-year measured from the date of randomization.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function.

Durations of normalization of peripheral neutrophils to >=1000 /microliter, platelet to >=100,000/microliter within 2 weeks of bone marrow biopsy/aspirate, and bone marrow to <=5 % blasts; independent of transfusions*; and no extramedullary leukemia.

* independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Duration of normalization of bone marrow to <=5% blasts; peripheral neutrophils >=1000 /microliter, platelet <=100,000 /microliter within 2 weeks of bone marrow biopsy/aspirate; independent of transfusions*; and no extramedullary leukemia.

*independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Duration of normalization of peripheral neutrophils to >=1000 /microliter, platelet to >=100,000/microliter within 2 weeks of bone marrow biopsy/aspirate, >=50% decrease in bone marrow blasts over pre-treatment but still >5%; independent of transfusions*

*independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Duration of HI

1. Erythroid response (HI-E) for patients with pre-treatment hemoglobin < 11 g/dL; Major response: >2 g/dL increase in hemoglobin; for RBC, transfusion independence* Minor response: 1 to 2 g/dL increase in hemoglobin; for RBC, a 50% decrease in transfusion requirements

2. Platelet response (HI-P) for pre-treatment platelet count <100,000/mm3; Major response: an absolute increase of platelet count by >=30,000/mm3; stabilization of platelet counts and platelet transfusion independence* Minor response: >=50% increase in platelet count with a net increase > 10,000/mm3 but <30,000/mm3

3. Neutrophil response (HI-N) for absolute neutrophil count (ANC) < 1,500/mm3 before therapy; Major response: >=100% increase, or an absolute increase of >500/mm3, whichever is greater Minor response: >=100% increase, but absolute increase < 500/mm3

   • independent of transfusions refer to no platelet transfusion for 1 week prior to achieving the response

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function

Failure to achieve at least hematologic improvement (HI), but no evidence of clinically significant progression for > 16 weeks.

Patients >= 70 years with histologically or pathologically confirmed AML; not treated by systemic therapy; on low-intensity therapy by investigator assessment or the patient has refused standard induction chemotherapy; no prior treatment with HMA or other anti-cancer agents; ECOG status 0-2; adequate hepatic and renal function