Phase Ⅲ Clinical Trial to Evaluate the Efficacy and Safety of TJ0113 Capsules in Patients With Early-Onset Parkinson's Disease

This study is a randomized, double-blind, multicenter, placebo-controlled Phase III clinical trial designed to evaluate the efficacy, safety, and Pop PK characteristics of TJ0113 Capsules in treating EOPD patients. This study plans to enroll approximately 300 EOPD participants, who will be randomized in a 1:1 ratio to two cohorts (Cohort 1: 200 mg dose group; Cohort 2: 400 mg dose group). Within each cohort, successfully screened participants will be stratified by stable use of dopamine receptor agonists (Yes vs. No) and stable use of Monoamine Oxidase B (MAO-B) inhibitors (Yes vs. No), and within each stratum, randomized in a 2:1 ratio to the TJ0113 Capsules group and the placebo group, with approximately 100 assigned to the TJ0113 Capsules group and approximately 50 assigned to the placebo group. In this trial, the sample size for the TJ0113 Capsules 200 mg group, TJ0113 Capsules 400 mg group, and placebo group will each be approximately 100 participants. After randomization, during the double-blind treatment period, participants will receive continuous oral administration of TJ0113 Capsules or placebo for 26 weeks. After the double-blind treatment ends, participants will enter the open-label treatment period. During the open-label treatment period, all participants will receive oral TJ0113 Capsules for 26 weeks, and the dose of TJ0113 Capsules will be consistent with the dose of the investigational product taken by the participant during the double-blind treatment period (regardless of whether they took TJ0113 Capsules or placebo during the double-blind treatment period). After the open-label treatment period ends, participants will continue to receive a safety follow-up for 1 week (telephone follow-up). From the screening period to the end of the double-blind treatment period, all participants must maintain their original background anti-PD medication regimen unchanged; from the open-label treatment period to the end of the study, changes to the dose of stably