Safety and Pharmacokinetics of AT-007 in Healthy Subjects and in Adult Subjects With Classic Galactosemia

AT-007 will be administered once daily before breakfast. Up to 4 different dose cohorts in part A; up to 4 dose cohorts in part B, up to 2 dose cohorts for part C, and up to 3 dose cohorts for part D will be enrolled in the study. The starting dose in Part A will be 0.5 mg/kg as a single dose. Subsequent doses in Part A and all doses in Parts B, C, and D will be based on the results of previous cohorts and/or previous parts of the study. Part B will start after all subjects in Part A have completed the study. Cohort C1 will be conducted simultaneously with Cohort B3 and using the same dose as Cohort B2. The dose for Cohort D1 will not be higher than the dose for Cohort B2. The second and third cohorts in Part D (D2 and D3) will not start until after all subjects in Cohorts B3 and B4, respectively, have completed the study and the dose levels will not be higher than those for Cohorts B3 and B4, respectively.

Matching placebo will be administered once in the morning before breakfast