This study examines the efficacy of three doses of IPX066 as compared to placebo in Parkinson's disease.

A randomized, double-blind, placebo-controlled, fixed-dose, parallel-arm study of three doses of IPX066 versus placebo.

Total of 427 subjects were screened and 381 were randomized and received one of the four treatment groups (1) placebo (N=92), (2) IPX066 145 mg LD (N=87) (3) IPX066 245 mg LD (N=104) (4) IPX066 390 mg LD (N=98) three times a day.

Study duration is approximately 30 weeks for each subject including 4 weeks of titration (up to 3 weeks of dose escalation and I week of stabilization for safe escalation to the allocated dose), and 26 weeks of maintenance.

During the titration phase:

The following dose strengths were used to titrate up to the final three strengths that were assigned to the three IPX066 treatment arms.

IPX066 95 mg LD capsule containing 95 mg LD and 23.75 mg CD. IPX066 145 mg LD capsule containing 145 mg LD and 36.25 mg CD. IPX066 195 mg LD capsule containing 195 mg LD and 48.75 mg CD. IPX066 245 mg LD capsule containing 245 mg LD and 61.25 mg CD.

During the maintenance phase:

IPX066 145 mg LD treatment arm received 145 mg LD and 36.25 mg CD. IPX066 245 mg LD treatment arm received 245 mg LD and 61.25 mg CD. IPX066 390 mg LD treatment arm received 390 mg LD and 97.50 mg CD.

Primary efficacy outcome measure was change from baseline in the sum of UPDRS Part II and Part III scores at the end of study or last value reported if subject discontinued prematurely.

Summary of Change From Baseline to End of Study in Mean Parkinson's Disease Questionnaire-39 (PDQ-39) Score.

Inclusion Criteria:

1. Able to understand and willing to voluntarily sign an informed consent form (ICF) and Health Insurance Portability and Accountability Act (HIPAA) authorization or local equivalent if applicable.
2. Diagnosed with idiopathic PD.
3. LD-naïve: defined as subjects not exposed to LD or catechol-O-methyl transferase inhibitors for more than 30 days and the exposure is not within 4 weeks prior to study enrollment.
4. If currently taking anticholinergic therapy, amantadine, or a monoamine oxidase type B (MAO-B) inhibitor, maintains a stable regimen for at least 4 weeks prior to Baseline, and agrees to maintain the stable regimen throughout study participation.
5. Agrees to use a medically acceptable method of contraception throughout the study and for 1 month after completing the study.
6. Able and willing to comply with the protocol, including availability for all scheduled clinic visits and telephone calls.

Exclusion Criteria:

1. Pregnant or breastfeeding.
2. Diagnosed with atypical Parkinsonism or any known secondary parkinsonian syndrome.
3. Prior functional neurosurgical treatment for PD or if such procedures are anticipated during study participation.
4. Use of nonselective MAO inhibitors.
5. Use of dopamine agonists within 30 days prior to Screening.
6. Unable to tolerate a placebo regimen, in the Investigator's opinion.
7. Treatment of psychosis with any antipsychotic.
8. History of seizure or epilepsy.
9. Active or prior medical condition or prior surgical procedure that would interfere with LD absorption.
10. History of narrow-angle glaucoma.
11. Subjects with a history of malignant melanoma.
12. History of myocardial infarction with residual atrial, nodal, or ventricular arrhythmias, upper gastrointestinal hemorrhage, or neuroleptic malignant syndrome.
13. Received any investigational medications during the 30 days prior to Screening.