IDH1 and central nervous system cancer: The promising, albeit preliminary, signs of efficacy seen in the non-enhancing cohort led to the design of the INDIGO study, a Phase III trial investigating the role of vorasidenib 50 mg QD in patients with residual or recurrent IDH1/2-mut grade 2 glioma, who are under radiographic surveillance following surgery and have not yet received radiation or chemotherapy (NCT04164901) (Table 3).