 An Open-Label, 2-Period, Fixed Sequence Study to Determine the Effect of Multiple Oral Doses of Itraconazole on the Single Dose Pharmacokinetics of AG 120 in Healthy Adult Subjects. Period 1 consists of a single oral dose of AG-120 will be administered at Hour 0 followed by PK sampling for 504 hours 21 days. In Period 2, multiple oral doses of itraconazole will be administered once daily QD for 18 consecutive days with a single oral dose of AG-120 coadministered at Hour 0 on Day 1. PK sampling for AG-120 will be taken for 504 hours 21 days following AG-120 dosing on Day 1. 