PH1

This study will be conducted to evaluate the efficacy and safety of YOLT-203 in children and adults with Primary Hyperoxaluria Type 1. After the initial randomized, 6-month double-blind, placebo-controlled period, participants who were initially assigned to placebo will receive a single-dose of YOLT-203 treatment whereas participants in the YOLT-203 group will receive a single-dose of placebo infusion.