**Evaluation of GM101 Injection in Patients With Parkinson's Disease** Parkinson's disease is a condition that affects movement and causes tremors. This study is testing the safety of GM101, a new treatment for Parkinson's disease. The treatment uses something called adeno-associated viruses (AAVs) to change certain brain cells into neurons that make dopamine, a chemical that's low in people with Parkinson's. **Key Points:** - **Study Length & Visits:** Participants will need to attend regular follow-ups and complete a patient diary. - **Eligibility:** Must be 40-70 years old, have Parkinson's for at least 5 years, and meet other health criteria. - **Risks:** Participants should not have other major illnesses or have had brain surgeries that might interfere with the study. To join, you must understand the trial details and agree to follow the study's rules. You cannot participate if you've had certain surgeries, other treatments, or have specific health conditions. The study is looking for participants who can live independently or have caregivers to assist them.