AGI-5198 is a selective inhibitor of the mutant form of isocitrate dehydrogenase 1 (IDH1), particularly the R132H variant. It is primarily used in research settings to study the role of mutant IDH1 in cancer metabolism, especially in gliomas and acute myeloid leukemia (AML). By inhibiting the abnormal enzyme activity, AGI-5198 reduces the production of the oncometabolite 2-hydroxyglutarate (2-HG), which is believed to contribute to tumor progression by altering cellular epigenetics and blocking differentiation. In preclinical models, AGI-5198 has demonstrated the ability to induce differentiation of tumor cells and suppress growth, making it a valuable tool compound for validating mutant IDH1 as a therapeutic target. Its use remains limited to laboratory research and has not been approved for clinical use.