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

This study includes 4 parts. In the first part, enrolled participants will receive a single dose of IV ATO, followed a week later by a single dose of SY-2101, SY-2101 will be administered to participants in either a fed or a fasted condition. A week after that, participants will receive a second, a single dose of SY-2101, with some participants taking this dose in a fed state and other participants taking this dose in a fasted condition. After each of these doses, blood draws and safety assessments will be performed. In the second part, enrolled participants will receive IV ATO according to the standard of care, with collection of blood and safety assessments. In the third part, enrolled participants who are documented to be in molecular remission will receive SY-2101 in place of IV ATO during the 4th cycle of consolidation, with the collection of blood and safety assessments throughout the cycle. In the fourth part, enrolled participants will receive two single-dose treatments of SY-2101 approximately one week apart.