A Multicenter Study to Evaluate Safety, Tolerability, and Clinical Responses of DSP-1083 Into Subjects With Parkinson's Disease

Inclusion Criteria:

1. Men or women aged ≥ 40 and < 70 years at the time of informed consent with aclinically established diagnosis of Parkinson's disease in accordance with theMovement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson'sDisease.

2. Subject has a clinically established diagnosis of PD for ≥ 4 years.

3. Subject has suboptimal control of PD symptoms, with optimized oral antiparkinsonianmedication regimen including levodopa/carbidopa monotherapy or levodopa/carbidopaplus antiparkinsonian medications, with stable dosing for ≥ 2months prior toscreening.

4. Subject has a L-DOPA response of ≥ 30% without the influence of antiparkinsonianmedications at Screening.

5. Subject has a Modified Hoehn and Yahr stage 3 - 4 in the Off state.

6. Subject has a pretreatment 18F-DOPA PET scan consistent with PD.

7. Subject has both On and Off states as demonstrated by the MDS-UPDRS Part III/IV andthe Hauser patient daily diary.

8. Subjects must meet the following race criteria: 2 of the up to 5 sentinel subjectswill be of Asian race, defined as having at least 2 grandparents who are Japanese,Taiwanese, Korean, or Chinese. Subjects in Cohort 2 can be of any race.

9. Subject is approved by the Enrollment Authorization Eligibility Committee followingreview of all required information collected during Screening.

Exclusion Criteria:

1. Subject has a typical parkinsonian syndrome (eg, progressive supranuclear palsy [PSP], multiple system atrophy [MSA], dementia with Lewy bodies [DLB], corticobasaldegeneration, Parkinson-plus syndrome, vascular parkinsonism, secondaryparkinsonism, hereditary parkinsonism).

2. Subject has non-PD neurological symptoms or evidence of non-PD brain disease (eg,tumor, inflammation, active or history of vascular disorder, history of cerebralhemorrhage, Alzheimer's disease, or other neurodegenerative disorder) based onneuroimaging and/or medical history that would preclude study participation.

3. Subject has psychiatric symptoms, cognitive impairment, depression, dementia, orother behavioral disorder that would preclude study participation based onInvestigator decision.

4. Subject has received previous striatal or other extrapyramidal system PD treatments,including deep-brain stimulation, central nervous system (CNS) ablation (eg,pallidotomy, thalamotomy), implanted cell, or gene therapy, and/or focusedultrasound therapy.

5. Subject has peak-dose dyskinesia of sufficient severity that precludes studyparticipation, defined as any item score of ≥ 3 (moderate dyskinesia) on the UDysRSPart 1B (Patient Dyskinesia Questionnaire) AND/OR any item score of ≥ 2 (moderatedyskinesia) on Part 3 (Objective Evaluation of Dyskinesia Disability) IntensityScale: Impairment. Subject has another type (eg, diphasic dyskinesia) or an unusualpattern of dyskinesia.

6. Subject has a history of, or concurrent abnormal immune function that may adverselyaffect the engraftment of the cell implants and use of adjunctiveimmunosuppressants.

7. The subject has the following clinical laboratory test results at Screening:

• Neutrophil count < 2,000/μL.

• Platelet count < 5.0 × 104/μL.

• Aspartate aminotransferase (AST), alanine aminotransferase (ALT) > 3.0 × upperlimit of normal.

• Total bilirubin > 1.5 × upper limit of normal.

• Persistent estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2.

• Poorly controlled blood glucose in diabetic subjects (glycosylated hemoglobin > 9.0%, or fasting serum glucose ≥ 200mg/dL).

8. Subject has any disorder that would contraindicate general anesthesia, conscioussedation or stereotactic surgery.

9. Subject has any clinically significant unstable medical condition or any clinicallysignificant chronic disease that would pose a risk to the subject or that mightconfound the results of the study. In cases in which the impact of the conditionupon risk to subject or study results is unclear, the Medical Monitor should beconsulted.