A Randomized, Double-Blind, Placebo-Controlled, Multicenter Phase IIb Clinical Trial to Evaluate the Efficacy and Safety of Oral VG081821AC Tablets Monotherapy (Without Concomitant Levodopa) in Patients With Early to Mid-Stage Parkinson's Disease
This study is testing a new oral medication called VG081821AC to see if it can help improve movement symptoms in people with early to mid-stage Parkinson's disease. VG081821AC works by blocking a protein in the brain called the adenosine A2A receptor, which may help improve motor function without using levodopa. The main goal is to measure changes in movement symptoms using a standard rating scale called the MDS-UPDRS Part III (Motor Examination). This scale evaluates how well participants can move, walk, and perform daily activities. The study will compare the scores before and after 12 weeks of treatment to see if VG081821AC improves movement symptoms better than the placebo. Currently, levodopa is the most common treatment for Parkinson's disease, but it can cause side effects over time. If VG081821AC works well, it could offer a new treatment option for people in the early to mid-stages of Parkinson's disease who want to delay or avoid starting levodopa. A total of 152 adults (aged 18-80 years) will be enrolled in this trial in China. Participants will be randomly assigned (like flipping a coin) to one of four groups: * VG081821AC 25 mg (taken twice daily) * VG081821AC 50 mg (taken twice daily) * VG081821AC 75 mg (taken twice daily) * Placebo (a pill with no active drug, taken twice daily) Participants will visit the study center 8 times to have their movement symptoms, safety, and overall health checked.
• Male or female aged 18 ≤ Age ≤ 80 at the time of signing the informed consent.
• Diagnosed with Parkinson's disease per the Chinese Diagnostic Criteria for Parkinson's Disease (2016 Edition), and time from initial diagnosis ≤ 7 years.
• Modified Hoehn-Yahr scale rated as 1\
⁃ 3 (inclusive) at screening.
• MDS-UPDRS Part III score ≥ 22 at screening.
• Have not taken anti-Parkinson drugs containing levodopa within 4 weeks prior to screening \[see main text section 5.7.1\] (Note: Patients who have previously taken levodopa-containing anti-Parkinson drugs can participate in this trial after a 4-week washout period).
• Patients receiving amantadine and/or anticholinergic drugs prior to screening must have been on a stable treatment regimen for at least 4 weeks prior to screening, and the dose must not change during the study.
• Women of childbearing potential must have a negative pregnancy test result at screening, and the participant must agree to use approved contraceptive measures throughout the study period.
• Must provide written informed consent and be willing and able to comply with the trial protocol (e.g., able to understand and complete questionnaires, follow the visit schedule, and use the medication).