Study Assessing Tolerability and Safety and Exploring the Immunogenicity and Therapeutic Activity of AFFITOPE® PD01A in PD-GBA Patients

Inclusion Criteria: * Confirmed diagnosis of Parkinson's disease and confirmed carrier status for a heterozygous GBA mutation (PDGBA) * Individuals who present in Hoehn\&Yahr Stages I/II/III and fulfill the United Kingdom Parkinson's Disease Society Brain Bank Criteria * Confirmed carrier status for a heterozygous GBA mutation (PDGBA)-The result of the MRI scan of the patient's brain has to be consistent with the diagnosis of PD * Written informed consent signed and dated by the patient and, preferentially, the caregiver (caregiver is not mandatory) * Age between 40 and 80 * In the investigator's opinion, does not have visual or auditory impairments that would reduce the patients' ability to complete study questionnaires or be unable to receive instructions for these * Female patients of childbearing potential are eligible if they use a medically accepted contraceptive method * A potential participant treated with conventional PD therapies must be on stable doses for at least 3 months prior to Visit 1 and during the entire trial period * Accepted PD medications include the following: levodopa (alone or in combination with benserazide, carbidopa), catechol-O-methyltransferase (COMT) inhibitors (entacapone, tolcapone), amantadine, non-ergot dopamine agonists (pramipexol, ropinirol, rotigotine), monoamine oxidase-B (MAO-B) inhibitors (rasagiline, selegiline) and anticholinergic medication * A potential participant should be on stable doses of all medications he/she is taking because of consisting illnesses according to medical history (except PD therapies, these will be recorded separately) for at least 30 days prior to Visit 1 if considered relevant by the investigator * Able to communicate well with the investigator, to understand and comply with the requirements of the study Exclusion Criteria: * Pregnant women * Sexually active women of childbearing potential who are not using a medically accepted birth control method * Participation in another clinical trial within 3 months before Visit 1 * History of questionable compliance to visit schedule; patients not expected to complete the clinical trial * Presence or history of allergy to components of the vaccine if considered relevant by the investigator * Contraindication for MRI imaging such as metallic implants (e.g. endoprosthesis, stents, cardiac pacemakers) which are not MR compatible at 3.0 Tesla with the given MR protocol, other foreign metal bodies (e.g. bullets, metal splinters, e.g.) or claustrophobia * Missing agreement to be informed about incident findings and consultation of a neuroradiologist * Contraindication for PET, that is, pregnancy and breast feeding. * Ongoing participation in other interventional studies or clinical trials using radiotracers * Dementia according to Diagnostic and Statistical Manual (DSM) IV criteria * History and/or presence of autoimmune disease, if considered relevant by the investigator * Recent (≤3 years since last specific treatment) history of cancer (Exceptions: non-melanoma skin cancer, intraepithelial cervical neoplasia) * Active infectious disease (e.g., Hepatitis B, C) * Presence and/or history of Immunodeficiency (e.g., HIV) * Significant systemic illness (e.g., chronic renal failure, chronic liver disease, poorly controlled diabetes, poorly controlled congestive heart failure, other deficiencies), if considered relevant by the investigator * History of significant psychiatric illness such as schizophrenia, bipolar affective disorder or psychotic depression * Parkinson-like disease secondary to drug therapy side effects (e.g., due to exposure to medications that deplete dopamine \[reserpine, tetrabenazine\] or block dopamine receptors \[neuroleptics, antiemetics\]) * Parkinson-plus syndromes (e.g., multiple system atrophy (MSA), progressive supranuclear palsy (PSP)), Dementia with Lewy Bodies (DLB) * Heredodegenerative disorders other than PDGBA, evidence for other genetic forms of PD (e.g. LRRK2, Parkin gene mutations) * Alcoholism or substance abuse within the past year (alcohol or drug intoxication) * Prior and/or current treatment with experimental immunotherapeutics including Intravenous Immunoglobulin (IVIG) * Prior and/or current treatment with immune modulating drugs: 1. Interleukins, Interferons, Tumor Necrosis Factor (TNF) and analogues, colony stimulating factor compounds 2. Ciclosporin, Tacrolimus, Sirolimus and analogues 3. Cytostatic drugs and certain DMARD for rheumatoid arthritis (and similar autoimmune disorders) (e.g. Cyclophosphamid, Azathioprin, methotrexate, sulfasalazine, leflunomide, sodium aurothiomalate (Gold), cyclosporin) and analogues 4. Systemic (gluco)corticoid therapy 5. All antibody therapies (e.g., anti cluster of differentiation 3 (CD3), anti cluster of differentiation 25 (CD25) or also anti-lymphocyte globulins) that might modulate, enhance or weaken an immune response * Change in dose of standard treatments for PD within 3 months prior to Visit 1 * Change in dose of previous and current medications which the patient is taking because of consisting illnesses according medical history (except PD therapies, these will be recorded separately) within the last 30 days prior to Visit 1, if clinically relevant * Treatment with deep brain stimulation * Venous status rendering it impossible to place an i.v. access