AG-120 is primarily used in the treatment of certain types of cancer, particularly those associated with mutations in the IDH1 gene. It works by inhibiting the mutated IDH1 enzyme, which plays a role in the abnormal growth of cancer cells. This targeted therapy helps to slow down or stop the progression of cancers such as acute myeloid leukemia (AML) and cholangiocarcinoma. By specifically targeting the mutated enzyme, AG-120 offers a more precise treatment option with potentially fewer side effects compared to traditional chemotherapy. It is often used in patients who have relapsed or are refractory to other treatments, providing a critical therapeutic alternative.