Additional Study Information: The purpose of this study is to: Test if the lifespan of study participants is increased when uproleselan is added to standard chemotherapy medicines compared to standard chemotherapy alone; test if the number of study participants achieving disease remission is increased when uproleselan is added to standard chemotherapy medicines compared to standard chemotherapy alone; measure the effect of uproleselan on oral mucositis when given with standard chemotherapy medicines compared to standard chemotherapy alone. Oral mucositis is a complication that leads to ulcers in the mouth that may result in pain and interfere with the ability to eat food and drink liquids; learn about the safety and tolerability of uproleselan when given with standard chemotherapy medicines compared to standard chemotherapy alone; and find out how much uproleselan is in the blood of study participants after being administered uproleselan. The study medication, uproleselan (GMI-1271), is experimental. That means the United States Food and Drug Administration (FDA) has not determined that it is safe and effective for any use, and has not approved it for use in humans.