A Study to Assess the Pharmacokinetics of Enasidenib (CC-90007) in Subjects With Moderate and Severe Hepatic Impairment.

Subjects will be enrolled in Groups 1 through 4 as follows: * Group 1: Approximately 6 to 8 male and female subjects with moderate hepatic impairment (with a Child-Pugh score of ≥ 7 to ≤ 9) will be enrolled in Group 1. * Group 2: Approximately 6 to 8 healthy male and female subjects with normal hepatic function will be enrolled in Group 2. Subjects in Group 2 will be matched to subjects in Group 1 with respect to sex, age (± 10 years), and weight (± 30 pounds). * Group 3: Approximately 6 to 8 male and female subjects with severe hepatic impairment (with a Child-Pugh score of ≥ 10 to ≤ 13) will be enrolled in Group 3. * Group 4: Approximately 6 to 8 healthy male and female subjects with normal hepatic function will be enrolled in Group 4. Subjects in Group 4 will be matched to subjects in Group 3 with respect to sex, age (± 10 years), and weight (± 30 pounds). This study employs a staged design as follows. * At least 4 subjects with moderate hepatic impairment must demonstrate satisfactory safety and tolerability for up to 8 days after dosing, before subjects with severe hepatic impairment may be dosed. * Two subjects with severe hepatic impairment must demonstrate satisfactory safety and tolerability for up to 8 days after dosing, before the remaining subjects with severe hepatic impairment may be dosed.