Study BRT-DA01-301 is a research project for adults with Parkinson's Disease (PD). PD is a brain disorder that causes shaking, stiffness, and trouble with balance. This study tests a treatment called bemdaneprocel to see if it helps PD symptoms. A Phase 3 study means it's in the later stages of testing to see if the treatment is safe and works well.

In this study, 102 participants will be split into two groups: some will get the treatment, and others will have a fake surgery (sham surgery) to compare effects. This is a double-blind study, so neither the participants nor the doctors know who gets the real treatment. This helps keep the results unbiased. Participants will be watched for at least 18 months, and possibly up to 5 years if they receive bemdaneprocel.

• This study requires a long-term commitment of up to 5 years.
• Participants must be willing to undergo a surgical procedure.
• Participants will receive treatments and be monitored closely by doctors.