RecruitingPhase 1Drug trialTazemetostat and Palbociclib With CPX-351for R/R AMLThis is a two-part phase Ib dose escalation study to evaluate the safety and preliminary efficacy of the combination of tazemetostat and CPX-351 (Part 1) and of pre-treatment with palbociclib followed by CPX-351 (Part 2) for patients with relapsed or refractory (R/R) acute myeloid leukemia (AML). Part 1 of the study will seek to establish the safety, tolerability, biological activity and recommended dose for further evaluation (RDFE) of tazemetostat in combination with standard-dose CPX-351. Part 2 of the study will seek to establish the safety, tolerability, biological activity RDFE of pre-treatment palbociclib prior CPX-351.