IDH1 and central nervous system cancer: A window-of-opportunity trial of vorasidenib and the IDH1 inhibitor ivosidenib randomized patients with recurrent nonenhancing WHO 2016 grade 2 or 3 IDH1mt glioma who were undergoing craniotomy to receive either ivosidenib, vorasidenib, or no treatment for 4 weeks preoperatively.