Selective allosteric inhibitor of mutant IDH2 (not IDH1 — ivosidenib is the IDH1 inhibitor) that suppresses production of the oncometabolite 2-hydroxyglutarate (2-HG). The mechanistic parallel to SDH deficiency is direct: both 2-HG (from IDH1/2 mutations) and succinate (from SDH loss) are α-ketoglutarate-competitive oncometabolites that inhibit the same family of α-KG-dependent dioxygenases, including TET1/2/3 DNA demethylases, KDM histone demethylases, and PHD prolyl hydroxylases (Nowicki & Gottlieb, FEBS J 2015, PMID 25864878; Yong et al., Nat Rev Nephrol 2019, PMID 31636445). This shared mechanism means that insights from IDH-inhibitor clinical programs — including the observation that IDH inhibition can reverse CIMP hypermethylation and restore cellular differentiation — are mechanistically transferable to SDH-deficient biology (Zhao et al., World J Gastroenterol 2020, PMID 32982110). Enasidenib itself is not active in SDH-deficient tumors (SDH loss does not produce 2-HG and IDH2 is not mutated), but it serves as a proof-of-concept that oncometabolite-driven epigenetic reprogramming is pharmacologically reversible. Drugs that directly address succinate accumulation or its downstream α-KG-dependent enzyme inhibition represent the analogous therapeutic strategy.