This study is a phase 1/2 first-in-human (FIH), study to evaluate the safety, tolerability, and pharmacokinetic (PK) of a single ascending dose (SAD) and repeat doses (RD) of UX053 in patients with GSD III. The SAD cohorts will be open-label (OL). There will be two types of RD cohorts, an open-label (OL-RD) and a randomized, double-blind (DB), and placebo-controlled (DB-RD).
The primary objective of the study is to evaluate the safety of UX053 in adults with Glycogen Storage Disease Type III (GSD III).