Solid state forms of Ivosidenib

Crystalline Form T11 of Ivosidenib, which is characterized by data selected from one or more of the following:

• i. an XRPD pattern having peaks at 14.3, 15.9, 21.2, 22.7 and 23.8 deg-2-theta±0.2 deg 2-theta;
• ii. an XRPD pattern as depicted in FIG. 12;
• iii. a solid state 13C—NMR spectrum with peaks at 178.4, 172.3, 151.8, 147.7 and 131.3 ppm±0.2 ppm;
• iv. a solid state 13C—NMR spectrum having the following chemical shift absolute differences from a peak at 57.8 ppm±2 ppm of 120.6, 114.5, 94.0, 89.9 and 73.5 ppm±0.1 ppm;
• v. a solid state 13C NMR spectrum having chemical shift difference from a peak at 178.4 ppm±1 ppm of 120.6 ppm±0.1 ppm;
• vi. a solid state 13C—NMR spectrum substantially as depicted in FIG. 27;
• or combinations of (i)-(vi).