The comparator regimen consists of IV ATO administered once daily during induction, given continuously, for up to a maximum of 60 days. During consolidation, IV ATO is administered once daily, per investigator's protocol. ATRA is administered orally in two divided daily doses during induction, given continuously until bone marrow remission (not exceeding 60 days). During consolidation, ATRA is taken orally in two divided daily doses following a 2-weeks-on / 2-weeks-off schedule within each 8-week cycle.

AUC is defined as the area under the plasma concentration-time curve from time zero to the last measurable concentration (AUC₀-t) and/or extrapolated to infinity (AUC₀-∞), calculated using noncompartmental methods.

Time-matched difference in change from baseline in QTcF interval between active treatment and placebo, derived from triplicate 12-lead ECGs at each post-dose time point

Change from baseline in EORTC QLQ-C30 global health status (0-100 scale)

Change from baseline in EQ-5D-5L index score (0-100)

OS is defined as the time from randomization to death from any cause. Participants who are alive at the time of analysis will be censored at the date last known to be alive.

EFS is defined as the time from randomization to the first occurrence of any of the following events: failure to achieve hematologic or molecular remission, relapse (hematologic or molecular), or death from any cause. Participants without an event at the time of analysis will be censored at the date of last adequate disease assessment.