Study to Assess the Safety, Tolerability and Preliminary Efficacy of NLX-112 Versus Placebo in L-dopa-induced Dyskinesia

Inclusion Criteria

• •1. Patient is 30 - 85 years old (inclusive) with a diagnosis of idiopathic PD according to the UK Parkinson's Disease Society Brain Bank Clinical Diagnosis criteria.
• •2. PD patient is stably and optimally treated with L-DOPA; other anti-PD treatments are allowed if used for at least 4 weeks of previous continuous treatment.
• •3. Patient agrees to be challenged with 150% of their normal L-DOPA dose (maximum L-DOPA dose 250 mg) 30 minutes prior to efficacy assessments at baseline (Visit 2) and at the 2 efficacy clinic visits (Visits 6 and 7).
• •4. PD patient exhibits troublesome peak-dose LID, confirmed by a score of at least 1 on part IV, item 33 (disability) of the UPDRS at screening (Visit 1) and at Day 1 (baseline, Visit 2).
• •5. At least 90 minutes in total for each 24-hour period during 2 days are indicated as "ON with troublesome dyskinesia" (according to the PD Home Dyskinesia Diary) prior to Day 1 (baseline, Visit 2).
• •6. Patient (and/or caregiver) demonstrates ability to accurately complete the PD Home Dyskinesia Diary entries during the screening visit.
• •7. Patient can read well enough to understand the informed consent document and other subject materials.
• •8. Female patients of child-bearing potential must have a negative urine pregnancy test at screening (Visit 1) and on Day 1 (Visit 2), must agree to avoid pregnancy during the study, and must practice abstinence (only allowed when this is the preferred and usual lifestyle of the subject) or must agree to use a highly effective method of contraception with a failure rate of \< 1% to prevent pregnancy (combined \[oestrogen and progestogen containing\] hormonal contraception associated with inhibition of ovulation \[oral, intravaginal, transdermal\], progestogen-only hormonal contraception associated with inhibition of ovulation \[oral, injectable, implantable\], intrauterine device \[IUD\] or intrauterine hormone-releasing system \[IUS\]) starting from 4 weeks prior to administration of the study drug and continuing during the course of the study until 4 weeks after last after IMP administration. Female subjects must agree to refrain from donating eggs from the date of dosing until 3 months after dosing with the IMP. Their male partner must agree to use a condom during the same time frame if he has not undergone vasectomy.
• •Females of non-childbearing potential are defined as pre-menopausal females who are sterilised (tubal ligation or permanent bilateral occlusion of fallopian tubes); or females who have undergone hysterectomy or bilateral oophorectomy; or post-menopausal defined as 12 months of amenorrhea (in questionable cases a blood sample with detection of follicle stimulating hormone \[FSH\] 25-140 IE/L is confirmatory).
• •Male patients must be either vasectomised, consent to use condom or practice sexual abstinence to prevent pregnancy and drug exposure of a partner and refrain from donating sperm from the date of dosing until 3 months after dosing with the IMP. Their female partner of child-bearing potential must use highly effective contraceptive methods with a failure rate of \< 1% to prevent pregnancy (see above) during the same period.