IDH1 and central nervous system cancer: AG-120 (ivosidenib, brand name Tibsovo), another selective IDH1-R132H inhibitor, was found to have robust D-2HG reduction and more favorable pharmacokinetics, although relevant to glioma, had a brain penetrance of only 4.1% (although it was thought to have greater brain penetrance in glioma patients who have a compromised blood–brain barrier) [21].