Amcasertib (BBI503) is primarily investigated for its potential in cancer therapy, specifically as a cancer stemness kinase inhibitor. It targets key signaling pathways involved in the survival and proliferation of cancer stem cells, which are often resistant to conventional treatments and contribute to tumor recurrence and metastasis. It has shown promising activity in preclinical models against a range of solid tumors, including those of the liver, colon, and pancreas, by suppressing tumor growth and preventing relapse. Its mechanism involves inhibiting STAT3 and other oncogenic kinases, thereby disrupting the self-renewal capacity of cancer stem cells. Due to its ability to target the root population of tumor cells, Amcasertib is being explored in clinical trials as a therapeutic option for advanced or refractory cancers, particularly where standard therapies have failed.