A new compound called RK-20449 identified by researchers from Japan and the United States effectively inhibits hematopoietic cell kinase, a molecule critical to leukemia stem cells (Saito Y et al. Sci Transl Med. 2013;5:181ra52). These cells are thought to be a powerful driver of cancer relapse in patients with acute myeloid leukemia (AML).
The researchers gave RK-20449 to immunocompromised mice that developed cancer after receiving transplanted leukemia stem cells from patients. After treatment, the numbers of circulating human leukemia cells decreased compared with numbers found in control animals; in some cases, the leukemia cells became undetectable in the blood after 2 to 3 weeks of treatment. The bone marrow and spleen of treated mice also contained significantly reduced numbers of leukemia cells compared with controls.
Hampton T. Targeting Leukemia Stem Cells. JAMA. 2013;309(21):2205. doi:10.1001/jama.2013.6701