XK-469 is an experimental anti-cancer drug, specifically a Topoisomerase IIβ (TOP2B) inhibitor, that shows promise for treating solid tumors and multi-drug resistant cancers. Developed from a quinoxaline class of compounds and first investigated by the National Cancer Institute, it works by interfering with DNA repair and replication, inducing cell cycle arrest, and promoting apoptosis (programmed cell death) in cancer cells. While it has demonstrated anti-tumor activity in preclinical models, it is currently in the preclinical phase of development for human use.