This research study will look at an experimental treatment medication called tamibarotene. Tamibarotene is a drug made from tretinoin, a drug used to treat acute promyelocytic leukemia (APL).

The goals of this study are:

• To see whether tamibarotene will cause leukemia to go into remission;
• To evaluate the usefulness and side effects of the treatment regimen; and
• To determine the amount of tamibarotene in a study participant's body and to see how the body gets rid of tamibarotene.

Information from this study may help doctors and patients with future treatments of APL.