Pevonedistat Plus Azacitidine Versus Single-Agent Azacitidine as First-Line Treatment for Participants With Higher-Risk Myelodysplastic Syndromes (HR MDS), Chronic Myelomonocytic Leukemia (CMML), or Low-Blast Acute Myelogenous Leukemia (AML)

Overall survival was defined as the time from randomization to death from any cause.

Kaplan-Meier estimates for the probability (expressed as a percentage) of participants that survived at the end of Month 6 from randomization are presented.

Kaplan-Meier estimates for the probability (expressed as a percentage) of participants that survived at the end of the first year from randomization are presented.

30-day mortality was defined as number of participants who died within 30 days from the first dose of study drug.

60-day mortality was defined as number of participants who died within 60 days from the first dose of study drug.

Time to AML transformation in HR MDS and CMML participants was defined as time from randomization to documented AML transformation as determined by the independent review committee (IRC) assessment. Participants who died before progression to AML were censored. Transformation to AML was defined, according to WHO classification, as a participant having 20% blasts in the blood or marrow and increase of blast count by 50%.

CR for HR MDS or CMML is defined as <=5% myeloblasts with normal maturation of all cell lines in the bone marrow, and greater than or equal to >=11 gram per deciliter (g/dL) hemoglobin (Hgb),>=100*10^9/liter (/L) platelets (pl),>=1.0*10^9/L neutrophils and 0% blasts in peripheral blood. CR for low-blast AML: morphologic leukemia-free state, neutrophils of more than 1.0*10^9/L and pl of >=100*10^9/L, transfusion independence, and no residual evidence of extramedullary leukemia. CR with incomplete blood count recovery (CRi) for low-blast AML: participants fulfill all of the criteria for CR except for residual neutropenia (<1.0*10^9/L) or thrombocytopenia (pl<100*10^9/L).

Disease responses for HR MDS or CMML are based on the International Working Group (IWG) Response Criteria for MDS. CR for HR MDS or CMML is defined as <=5% myeloblasts with normal maturation of all cell lines in the bone marrow, and >=11 g/dL Hgb, >=100*10^9/L platelets (pl), >=1.0*10^9/L neutrophils and 0% blasts in peripheral blood. Marrow CR: Bone marrow: <=5% myeloblasts and decrease by >=50% over pretreatment.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS. CR: <=5% myeloblasts with normal maturation of all bone marrow cell lines, >=11 g/dL Hgb, >=100*10^9/L pl, >=1.0*10^9/L neutrophils,0% blasts in peripheral blood. Marrow CR: Bone marrow: <=5% myeloblasts and decrease by >=50% over pretreatment. PR: all CR criteria met except bone marrow blasts >=50% decrease over pretreatment but still >5%. HI: Hgb increase >=1.5 g/dL if <11 g/dL; pl increase >=30*10^9/L if baseline>20*10^9/L or increase from <20*10^9/L to >20*10^9/L and by at least 100%; neutrophil increase by 100% and absolute increase of >0.5*10^9/L if baseline <1.0*10^9/L.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS. CR: <=5% myeloblasts with normal maturation of all bone marrow cell lines, >=11 g/dL Hgb, >=100*10^9/L pl, >=1.0*10^9/L neutrophils,0% blasts in peripheral blood. Marrow CR: Bone marrow: <=5% myeloblasts and decrease by >=50% over pretreatment. PR: all CR criteria met except bone marrow blasts >=50% decrease over pretreatment but still >5%.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS. CR: <=5% myeloblasts with normal maturation of all bone marrow cell lines, >=11 g/dL Hgb, >=100*10^9/L pl, >=1.0*10^9/L neutrophils,0% blasts in peripheral blood. Marrow CR: Bone marrow: <=5% myeloblasts and decrease by >=50% over pretreatment. PR: all CR criteria met except bone marrow blasts >=50% decrease over pretreatment but still>5%. HI: Hgb increase >=1.5 g/dL if baseline <11 g/dL; pl increase >=30*10^9/L if baseline>20*10^9/L or increases from <20*10^9/L to >20*10^9/L and by at least 100%; neutrophil increases by 100% and absolute increases of >0.5*10^9/L if baseline <1.0*10^9/L.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS; for low-blast AML on Revised IWG Response Criteria for AML. Overall response=CR or PR for HR MDS/CMML and CR + CRi + PR for low-blast AML. CR for HR MDS/CMML: <=5% myeloblasts with normal maturation of all bone marrow cell lines, >=11 g/dL Hgb, >=100*10^9/L pl, >=1.0*10^9/L neutrophils, 0% blasts in peripheral blood and PR: all CR criteria met except bone marrow blasts >=50% decrease over pretreatment but still>5%. For low-blast AML-CR:morphologic leukemia-free state>1.0*10^9 neutrophils, >=100*10^9/L pl, transfusion independence, no residual evidence of extramedullary leukemia; CR with incomplete blood count recovery (CRi): fulfill CR criteria except residual neutropenia <1.0*10^9/L or pl <100*10^9/L; PR: all CR hematological values but >=50% decrease in bone marrow aspirate.

OR2=participant with best overall response of CR+PR+HI in HR MDS/CMML participants,or of CR+CRi+PR in low-blast AML participants.CR:≤5% myeloblasts with normal maturation of all bone marrow(BM)cell lines,≥11g/dL Hgb,≥100*10^9/L pl,≥1.0*10^9/L neutrophils,0% blasts in peripheral blood;PR:all CR criteria met except BM blasts ≥50% decrease over pretreatment but still >5%;HI:Hgb increase(inc) ≥1.5g/dL if baseline(BL)<11 g/dL;pl inc≥30*10^9/L if BL>20*10^9/L or inc from <20*10^9/L to >20*10^9/L and by 100%;neutrophil inc by 100%;absolute inc of >0.5*10^9/L if BL<100*10^9/L.For low-blast AML-CR:morphologic leukemia-free state >1.0*10^9 neutrophils,≥100*10^9/L pl,transfusion independence,no residual evidence of extramedullary leukemia;CR with incomplete blood count recovery:fulfill CR criteria except residual neutropenia <1.0*10^9/L or pl<100*10^9/L;PR:all CR hematological values but ≥50% decrease in BM aspirate.Number of responders determined by independent review committee(IRC) assessment.

Duration of CR is first documented CR to the first documentation of PD or relapse from CR (participants with low-blast AML) or relapse after CR or PR (participants with HR MDS/CMML). Disease responses for HR MDS or CMML are based on the Modified IWG Response Criteria for MDS and for low-blast AML on the Revised IWG Response Criteria for AML. CR for HR MDS or CMML is defined as <=5% myeloblasts with normal maturation of all cell lines in the bone marrow, and greater than or equal to >=11 g/dL Hgb,>=100*10^9/L pl,>=1.0*10^9/L neutrophils and 0% blasts in peripheral blood. CR for low-blast AML: morphologic leukemia-free state, neutrophils of more than 1.0*10^9/L and pl of >=100*10^9/L, transfusion independence, and no residual evidence of extramedullary leukemia. CR with incomplete blood count recovery (CRi) for low-blast AML: participants fulfill all of the criteria for CR except for residual neutropenia (<1.0*10^9/L) or thrombocytopenia (pl<100*10^9/L).

Duration of CR is first documented CR to the first documentation of PD or relapse from CR (participants with low-blast AML). Disease responses for low-blast AML were based on the Revised IWG Response Criteria for AML. CR is defined as <=5% myeloblasts with normal maturation of all cell lines in the bone marrow, and greater than or equal to >=11 g/dL hemoglobin (Hgb),>=100*10^9/liter (/L) platelets (pl),>=1.0*10^9/L neutrophils and 0% blasts in peripheral blood. CR for low-blast AML: morphologic leukemia-free state, neutrophils of more than 1.0*10^9/L and pl of >=100*10^9/L, transfusion independence, and no residual evidence of extramedullary leukemia. CR with incomplete blood count recovery (CRi) for low-blast AML: participants fulfill all of the criteria for CR except for residual neutropenia (<1.0*10^9/L) or thrombocytopenia (pl<100*10^9/L).

Duration of OR: response to first documentation of PD or relapse from CR for low-blast AML or relapse after CR or PR for HR MDS/CMML. Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS; for low-blast AML on Revised IWG Response Criteria for AML. Overall response=CR+PR for HR MDS/CMML and CR+Cri+ PR for low-blast AML.CR for HR MDS/CMML:<=5% myeloblasts with normal maturation of all bone marrow cell lines,>=11 g/dL Hgb,>=100*10^9/L pl,>=1.0*10^9/L neutrophils,0% blasts in peripheral blood and PR:all CR criteria met except bone marrow blasts>=50% decrease over pretreatment but still >5%. For low-blast AML-CR: morphologic leukemia-free state >1.0*10^9 neutrophils,>=100*10^9/L pl, transfusion independence, no residual evidence of extramedullary leukemia; CR with CRi: fulfill CR criteria except residual neutropenia <1.0*10^9/L or pl <100*10^9/L; PR: all CR hematological values but >=50% decrease in % of blasts in bone marrow aspirate.

Duration of OR2: from date of first documentation of CR+PR+HI to first documentation of PD/relapse after CR/PR for responders of CR+PR+HI for HR MDS/CMML and CR,CRi,PR for low-blast AML. For HR MDS/CMML-CR:<=5% myeloblasts with normal maturation of all bone marrow cell lines,>=11 g/dL Hgb, >=100*10^9/L pl,>=1.0*10^9/L neutrophils, 0% blasts in peripheral blood; PR: all CR criteria met except bone marrow blasts>=50% decrease over pretreatment, still >5%; HI:Hgb inc >=1.5 g/dL if baseline <11 g/dL; pl inc>=30*10^9/L if baseline>20*10^9/L or inc from<20*10^9/L to>20*10^9/L by at least 100%; neutrophil inc by 100% and absolute inc of >0.5*10^9/L if baseline <1.0*10^9/L.For low-blast AML-CR: morphologic leukemia-free state,>1.0*10^9 neutrophils,>=100*10^9/L pl, transfusion independence, no residual evidence of extramedullary leukemia;CRi: fulfill CR criteria except residual neutropenia<1.0*10^9/L or pl <100*10^9/L;PR:all CR hematological values but>=50% decrease in bone marrow aspirate.

A participant was defined as RBC or platelet-transfusion independent if he/she received no RBC or platelet transfusions for a period of at least 8 weeks before the first dose of study drug through 30 days after the last dose of any study drug. Rate of transfusion independence was defined as number of participants who became transfusion independent divided by the number of participants who were transfusion dependent at Baseline.

Duration of RBC and platelet transfusion independence was defined as the longest time between the last RBC and/or platelet transfusion before the start of the RBC and/or platelet transfusion-independent period and the first RBC and/or platelet transfusion after the start of the transfusion-independent period, which occurs >= 8 weeks later.

Time to first CR or PR is defined as the time from randomization to first documented CR or PR, whichever occurs first. Disease responses for HR MDS or CMML or low-blast AML cycle 6 are based on Modified IWG Response Criteria for MDS and for low-blast AML on Revised IWG Response Criteria for AML. For HR MDS or CMML-CR:<=5% myeloblasts with normal maturation of all bone marrow cell lines,>=11 g/dL Hgb,>=100*10^9/L pl,>=1.0*10^9/L neutrophils, 0% blasts in peripheral blood; PR: all CR criteria met except bone marrow blasts>=50% decrease over pretreatment but still>5%; For low-blast AML-CR: morphologic leukemia-free state,>1.0*10^9/L neutrophils, pl>=100*10^9/L, transfusion independence, no residual evidence of extramedullary leukemia; CR with incomplete blood count recovery: fulfill CR criteria except residual neutropenia<1.0*10^9/L or pl <100*10^9/L; PR: all CR hematological values but with a decrease of at least 50% in the percentage of blasts to 5% to 25% in the bone marrow aspirate.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS. HI: Hgb increase >=1.5 g/dL if baseline <11 g/dL; pl increase >=30*10^9/L if baseline >20*10^9/L or increase from <20*10^9/L to >20*10^9/L by at least 100%; neutrophil increase by 100% and absolute increase of >0.5*10^9/L if baseline <1.0*10^9/L.

Inpatient hospital admission data was collected through transformation to AML (HR MDS/CMML participants) or disease progression (low-blast AML participants) or until initiation of subsequent therapy (all participants), whichever occurred first. Transformation to AML is defined, according to WHO Classification, as a participant having 20% blasts in the blood or marrow and increase of blast count by 50%.

Time to PD, relapse after CR(low-blast AML), relapse after CR or PR(HR MDS/CMML), or death,defined as time from date of randomization until date of first documentation of PD,relapse after CR(low-blast AML),relapse after CR or PR(HR MDS/CMML),or death due to any cause, whichever occurs first. In HR MDS/CMML,PD: Participants with<5% blasts:>=50% inc >5% blasts, with 5%-9% blasts:>=50% inc>10% blasts, with 10%-19% blasts:>=50% inc >20% blasts,with 20%-30% blasts, at least 50% decrement from maximum remission/response in granulocytes or pl or reduction in Hgb by>=2 g/dL/new transfusion dependence.Relapse after CR or PR: return to pretreatment bone marrow blast %/Decrement of >=50% from maximum remission/response levels in granulocytes/pl/reduction in Hgb conc.>=1.5 g/dL/transfusion dependence. In AML,PD:>50% inc in bone marrow blasts to >30% blasts,>50% inc in circulating blasts to>30% blasts in peripheral blood, Development of extramedullary disease/new sites of extramedullary leukemia.

The EORTC QLQ-C30 contains 30 items across 5 functional scales (physical, role, cognitive, emotional, and social), 9 symptom scales (fatigue, nausea and vomiting, pain, dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and financial difficulties) and a global health status/QOL scale. Most of the 30 items have 4 response levels (not at all, a little, quite a bit, and very much), with 2 questions relying on a 7-point numeric rating scale. Raw scores are converted into scale scores ranging from 0 to 100. For the functional scales and the global health status/QOL scale, higher scores represent better QOL; for the symptom scales, lower scores represent better QOL. The change from baseline at end of treatment is reported.

Disease responses for HR MDS/CMML based on Modified IWG Response Criteria for MDS; for low-blast AML on Revised IWG Response Criteria for AML. Overall response=CR + PR for HR MDS/CMML and CR + CRi + PR for low-blast AML. CR for HR MDS/CMML: <=5% myeloblasts with normal maturation of all bone marrow cell lines, >=11 g/dL Hgb, >=100*10^9/L pl, >=1.0*10^9/L neutrophils,0% blasts in peripheral blood and PR: all CR criteria met except bone marrow blasts>=50% decrease over pretreatment but still>5%. For low-blast AML-CR: morphologic leukemia-free state, >1.0*10^9 neutrophils,>=100*10^9/L pl, transfusion independence, no residual evidence of extramedullary leukemia; CR with incomplete blood count recovery (CRi): fulfill CR criteria except residual neutropenia<1.0*10^9/L or pl<100*10^9/L; PR: all CR hematological values but>=50% decrease in the percentage of blasts to 5% to 25% in bone marrow aspirate.

Event was defined as death or transformation to AML in participants with MDS or CMML, whichever occurred first. Transformation to AML was defined, according to World Health Organization (WHO) Classification as a participant having >20% blasts in the blood or marrow and increase of blast count by 50%. Event was defined as death in participants with low-blast AML.

OS was calculated from date of randomization to the date of death due to any cause. Participants without documented death at the time of the analysis were censored as of the date the participant was last known to be alive.

Responses for HR MDS/CMML are based on Modified International Working Group (IWG) Response Criteria for MDS and for low-blast AML on Revised IWG Response Criteria for AML. Overall response=CR and PR for HR MDS/CMML and CR+CR with incomplete blood count recovery(CRi)+PR for low-blast AML. CR for HR MDS/CMML:<=5% myeloblasts with normal maturation of all bone marrow cell lines,>=11g/dL hemoglobin (Hgb),>=100*10^9/L platelet (pl),>=1.0*10^9/L neutrophils, 0% blasts in peripheral blood, and PR:all CR criteria met except bone marrow blasts >=50% decrease over pretreatment but still >5%. For low-blast AML-CR:morphologic leukemia-free state,>1.0*10^9 neutrophils, >=100*10^9/L pl, transfusion independence, no residual evidence of extramedullary leukemia;CRi:fulfill CR criteria except residual neutropenia <1.0*10^9/L/thrombocytopenia (pl<100*10^9/L); PR:all CR hematological values but>=50% decrease in percentage of blasts to 5%-25% in bone marrow aspirate.