Upon randomization, subjects will be randomly assigned to either AVTX-801 1.5 g/kg/day (not to exceed 50 g/day) or blinded withdrawal for 16 weeks. Efficacy will be assessed from the Baseline Visit (Day 1) to the End of Double-blind Period Visit (Day 112).~Subjects who are D-galactose treatment-naïve may enter the randomized, double blind portion of the study after completing at least 6 weeks of stable doses of AVTX-801 at 1.5 g/kg/day. Dosing with AVTX-801 will begin with 0.25 g/kg/day for at least 14 days. Doses may be increased every 14 days at the following schedule: 0.5 g/kg/day, 1.0 g/kg/day, and 1.5 g/kg/day. Dose escalation will be based on the Investigator's assessment of individual subject tolerability and improvement in the key clinical laboratory parameters (ATIII, creatine kinase [CK], ALT, AST, and fasting blood glucose). Maximum daily dose should not exceed 50 g/kg/day. Once the Investigator has determined a safe, effective, and well tolerated dose, a 6-week run in period will begin with the selected dose. Upon completion of the 6-week run-in period, subject will be randomized and proceed into the study.~During the randomized portion of the study, subjects will be closely monitored for clinical signs and symptoms related to or suspected to be related to withdrawal of D galactose therapy; specifically, recurrent or prolonged hypoglycemia, prolonged elevation of ALT, and decreases in ATIII.
This is a multicenter, randomized, double-blind, withdrawal study assessing the efficacy, safety, and tolerability of AVTX-801 in subjects with PGM1-CDG.