Study DTX401-CL301 is a phase 3, randomized, double-blind, placebo-controlled study to determine the efficacy and confirm the safety of DTX401 in patients 8 years and older with glycogen storage disease type Ia (GSDIa). Participants will be randomized 1:1 to DTX401 or placebo group, and followed closely for 48 weeks. At week 48 eligible participants will cross over and receive DTX401 if they had previously received placebo or placebo if they had previously received DTX401, and will be followed closely for an additional 48 weeks. After completion of week 96 or early withdrawal, participants will be offered enrollment into a Disease Monitoring Program (DMP) where they will be followed for at least 10 years post DTX401 infusion.
The primary objectives of this study are to evaluate the efficacy of DTX401 to reduce or eliminate dependence on exogenous glucose replacement therapy to maintain euglycemia and to maintain or improve the quality of glucose control.