In APL t(15;17), part of RAR-alpha gene on 17q, is translocated to 15q and fused to another gene, PML. The fusion-gene product (pml-rar alpha) causes failure of promyelocytes to differentiate and blocks apoptosis.
The drug used in APL allows for differentiation of the leukemic cell. What is it?
Toxicities include: headache, dryness of the skin and mucous membranes, nausea, vomiting, and moderate bone and joint pain are also seen. "Retinoic Acid Syndrome"
Response: complete remissions in 64-100% of patients with duratiosn of 2 to 13+ months
All-trans-Retinoic Acid (Tretinoin)