10. Female patients with reproductive potential must agree to undergo medically supervised pregnancy tests prior to starting study drug. The first pregnancy test will be performed at screening (within 7 days prior to first study drug administration); the second will be performed on the day of the first study drug administration and must be confirmed negative prior to dosing. Patients with reproductive potential are defined as sexually mature women who have not undergone a hysterectomy, bilateral oophorectomy or tubal occlusion or who have not been naturally postmenopausal (i.e., who have not menstruated at all) for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months). Females of reproductive potential, as well as fertile men and their partners who are female of reproductive potential, must agree to use two effective forms of contraception (including at least one barrier form) from the time of giving informed assent/consent, during the study, and for 90 days (both females and males) following the last dose of AG-120. Effective forms of contraception are defined as hormonal oral contraceptives, injectables, patches, intrauterine devices, intrauterine hormone-releasing systems, bilateral tubal ligation, condoms with spermicide, or male partner sterilization.