Phase 2 Parkinson's Disease Trial, Recruiting

Written by an AI model from ClinicalTrials.gov eligibility criteria and checked on a sample basis. Please confirm against the original criteria.

Who might be able to join this trial:

• People aged 30 to 75 years old at the time of signing the consent form.
• People who have been diagnosed with Parkinson's disease between 4 and 20 years ago, meeting specific recognised diagnostic guidelines.
• People whose Parkinson's symptoms when their medication is not working fall within a certain range of severity, based on a standard rating scale (H-Y stage 2.5–4.0).
• People whose movement symptoms score above a certain threshold on a standard assessment (MDS-UPDRS-III score above 35), and whose symptoms improve by more than 30% when medication is working, confirmed across two screening visits.
• People whose symptom scores remain stable between the two screening visits.
• People who have been on a stable dose of Parkinson's medication for at least 4 weeks before starting the study.
• People whose Parkinson's medication dose and schedule have not changed during the screening period.
• People who are medically suitable to undergo brain surgery under general anaesthetic.
• People whose blood test results during screening fall within acceptable ranges, including healthy levels of immune cells, platelets, liver function markers, kidney function markers, and related values (confirm specific values with trial site).
• People who agree to delay any additional brain surgery, including deep brain stimulation (DBS), until at least 12 months after the study surgery, unless a neurologist recommends otherwise.
• People who agree not to join any other treatment study for 24 months after the surgery.
• People who are able to attend all study visits and complete all required scans, including brain MRI, CT, and PET scans.
• People with a body mass index (BMI) between 18 and 32, and a minimum weight of 45 kg at screening.
• People who are willing to use contraception for 12 months after surgery, in line with local guidelines for clinical trial participants.
• People who are able to understand the purpose of the trial and sign the consent form.
• People who agree not to receive a COVID-19 vaccine within 14 days before surgery, and no other vaccines within 30 days after surgery.

Who may not be able to join:

• People whose Parkinson's is classified as an atypical or secondary form, rather than standard Parkinson's disease.
• People who have previously had brain surgery, including pallidotomy, deep brain stimulation, stereotactic surgery, or radiation to the brain or spinal cord.
• People whose previous brain scans showed certain abnormalities such as brain injury, abnormal blood vessels, fluid on the brain, or tumours, where these could increase the risk of surgery.
• People who have previously received any type of cell therapy.
• People who have used high-dose steroid medications (such as prednisone at 20 mg/day or equivalent) for 14 days or more in the 3 months before signing the consent form (topical steroids are not included).
• People who have used immune-suppressing medications for 14 days or more in the 3 months before signing the consent form.
• People who have used certain psychiatric medications, such as antidepressants or mood stabilisers, in the 3 months before signing the consent form, if the trial doctors consider these could affect study results.
• People who have used botulinum toxin or similar treatments for muscle stiffness or spasms in the 6 months before signing the consent form, if considered likely to affect study results.
• People currently taking part in, or who have taken part in, another clinical study within 3 months before screening.
• People whose trial doctors consider them unlikely to follow the study requirements reliably.
• People with a history of dementia or serious cognitive (thinking and memory) problems, or where significant cognitive impairment is detected during screening, or whose cognitive impairment score on a standard scale is above a certain threshold.
• People with severe depression, as measured by a standard rating scale (HAMD score of 24 or above at screening).
• People with severe anxiety, as measured by a standard rating scale (HAMA score of 29 or above at screening).
• People with a history of psychiatric conditions that the trial doctors consider unsuitable for participation, or people who have had thoughts of suicide or suicide attempts in the past year or currently.
• People with blood clotting abnormalities detected during screening.
• People who are unable to temporarily stop blood-thinning or anti-clotting medications for at least 5 days before surgery.
• People who have had active blood clotting disorders or significant bleeding problems in the 3 months before signing the consent form.
• People with a current or past history of certain serious health conditions, including:
  • Moderate to severe heart failure, unstable chest pain, or heart attack
  • Serious heart rhythm problems, including certain types of heart block or abnormal heart electrical activity
  • Long QT Syndrome (a heart rhythm condition)
  • Previous heart or vascular surgery
  • Stroke or mini-stroke (TIA) within 3 months before signing the consent form, if considered unsuitable by trial doctors
  • Bleeding around the brain (subarachnoid haemorrhage)
  • Mitochondrial disease, multiple sclerosis, Alzheimer's disease, or other brain-degenerative conditions
  • Serious blood vessel conditions such as aortic aneurysm or significant narrowing of a major artery, if considered unsuitable by trial doctors
  • Any previous or current cancer
  • Immune system disorders, including autoimmune conditions or conditions that weaken the immune system
  • Brain injury with loss of consciousness and lasting neurological effects
  • Active epilepsy or current use of anti-epilepsy medications
• People with poorly controlled high blood pressure (above 160/100 mmHg despite medication), or severe drops in blood pressure when standing.
• People with poorly controlled diabetes (based on specific blood sugar test values — confirm with trial site).
• People with significant kidney or liver problems detected at screening.
• People with significant abnormalities in immune system test results at screening.
• People with medical reasons that prevent them from having surgery, such as having a cochlear implant, heart pacemaker, or cardiac defibrillator; or people who have had a brain cell implant procedure, or other surgery within 6 months before screening that trial doctors consider relevant.
• People with other serious conditions affecting other body systems, such as severe lung disease or moderate to severe asthma (confirm specific criteria with trial site).
• People who have had a serious infection requiring antibiotics within 2 weeks before signing the consent form.
• People with any currently active infection, including HIV, active COVID-19, syphilis, hepatitis B or C (where test results are above normal range), or untreated tuberculosis, or any other active infection that trial doctors consider may affect participation or results.
• People with alcohol or drug dependency.
• People with known allergies or contraindications to any medications used during surgery or throughout the study, including immune-suppressing drugs, levodopa, or similar drug classes such as macrolide antibiotics.
• Women who could become pregnant and are not surgically sterilised, not postmenopausal, or unwilling to use effective contraception during the study; and women who are currently breastfeeding.
• Men who are not surgically sterilised and are unwilling to use effective contraception during the study.
• People who have received electroconvulsive (electric shock) therapy within 30 days before surgery.
• People currently being treated with certain medications including antipsychotics, apomorphine, or levodopa/carbidopa delivered by infusion.
• People with severe uncontrolled movement complications in both medicated and unmedicated states.
• People who have received, or plan to receive, a live vaccine within 4 weeks before the study.
• People with other significant medical conditions that trial doctors consider make them unsuitable for participation.

Important: Always verify eligibility with the trial site directly before applying.