RTID-05. INDIGO: A GLOBAL, RANDOMIZED, DOUBLE-BLIND, PHASE 3 STUDY OF VORASIDENIB (AG-881) VS PLACEBO IN PATIENTS WITH RESIDUAL/RECURRENT GRADE II GLIOMA WITH AN ISOCITRATE DEHYDROGENASE 1/2 (IDH1/2) MUTATION. (9th November 2020)