Evaluation of GM101 Injection in Patients With Parkinson's Disease

This study is testing GM101, a gene therapy delivered by brain surgery, for people with advanced Parkinson's disease whose symptoms are no longer well controlled by medication. The therapy uses a modified virus to deliver genes that may help restore normal brain cell function in the region affected by Parkinson's. **You may be eligible if...** - You are aged 40–70 - You have had Parkinson's disease for 5 or more years - Your symptoms are advanced (Hoehn-Yahr stage 4–5 when medication is worn off) - You have a significant response to levodopa when it works (improvement >30%) - Your symptoms are not well controlled despite optimal medication - You are healthy enough to undergo brain surgery under anesthesia - Your weight is between 40–110 kg and BMI is 18–34 **You may NOT be eligible if...** - You have a form of parkinsonism that is not true Parkinson's disease - You have previously had deep brain stimulation or other brain surgery - You have had a heart attack, severe heart failure, stroke, or brain bleed - You have a history of cancer - You have received previous cell or gene therapy - You have active HIV, hepatitis B, hepatitis C, or tuberculosis - You are pregnant or planning to become pregnant within 2 years Talk to your doctor to see if this trial is right for you.