A Study for Oral SY-2101 for Participants With Acute Promyelocytic Leukemia

SY-2101 is being studied as a treatment for participants with a type of leukemia called acute promyelocytic leukemia (APL). SY-2101 is an oral formulation of a drug called arsenic trioxide (ATO). ATO is already used to treat APL in a formulation that is given as an intravenous (IV) infusion (through a needle in the arm). SY-2101 is a formulation of ATO that is taken orally (by mouth). This trial will include participants with APL in remission, who are receiving standard of care (SOC) treatment with all-trans-retinoic acid (ATRA) and IV ATO, during the consolidation phase of chemotherapy or within the past 6 months. The participants in this trial will receive continued treatment with ATO and ATRA to help keep their cancer from coming back. There will be some weeks when participants receive IV ATO and others when they receive SY-2101 (ATO taken orally). Participants with high-risk APL may be eligible for part 1 or 4 of the study for the 6 months following completion of their standard of care ATRA and ATO treatment.