This Clinical Trial is Designed to Evaluate the Safety, Tolerability, Feasibility and Preliminary Efficacy of NouvNeu001 (Human Dopaminergic Progenitor Cells Injection) in Patients With Parkinson's Disease.

This early-phase study is testing a new cell-based treatment called NouvNeu001 — human dopamine-producing brain cells injected into the brain — to see if it is safe and may slow or improve symptoms in people with Parkinson's disease. **You may be eligible if...** - You are between 30 and 75 years old - You were diagnosed with Parkinson's disease 4 to 20 years ago - Your symptoms are moderate to severe, especially during "off" periods when medication is wearing off - Your symptoms improve meaningfully when you take levodopa - Your medication doses have been stable for at least 4 weeks **You may NOT be eligible if...** - You have significant cognitive decline or dementia - You have had deep brain stimulation (DBS) surgery - You have other neurological conditions that may mimic Parkinson's - You have significant heart, immune, or other major medical conditions Talk to your doctor to see if this trial is right for you.