An orally bioavailable, small molecule, selective and competitive antagonist of peroxisome proliferator activated receptor alpha (PPARa), with potential immunomodulating and antineoplastic activities. Upon oral administration, TPST-1120 targets, binds to and blocks the activity of PPARa, thereby blocking transcription of PPARa target genes leading to an intracellular metabolism shift from fatty acid oxidation (FAO) to glycolysis in FAO-dependent tumors and reducing the production of fatty acids in the tumor microenvironment (TME). As fatty acids are essential for tumor cell growth in FAO-dependent tumor cells and are needed for the metabolism of suppressive immune cells in the TME, including regulatory T-cells (Tregs), reducing the amount of fatty acids leads to a direct killing of FAO-dependent tumor cells. It also skews macrophages from the immune suppressive M2 phenotype to an effector M1 phenotype and facilitates the cytotoxicity of immune effector cells, thereby stimulating an anti-tumor immune response and further killing tumor cells. TPST-1120 also restores the natural inhibitor of angiogenesis thrombospondin-1 (TSP-1) and stimulator of interferon genes (STING) in the TME. PPARa, a ligand-activated nuclear transcription factor and metabolic checkpoint, regulates the expression of FAO genes and lipid metabolism. It plays a key role in immunosuppression in the TME. FAO is a metabolic pathway essential to tumor growth, survival and immunosuppression.