Evaluation of Safety and Tolerability of ENT-01 for the Treatment of Parkinson's Disease Related Constipation

This is a Phase 1/2a study to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of an orally-administered medication to relieve symptoms of constipation associated with Parkinson's Disease. Ten patients will be enrolled in Phase 1, and will be studied over an 8-12 week period. Forty patients will be enrolled in Phase 2, and will be studied over an 8-10 week period. All subjects will receive the study drug during one of the observational periods of the study.

Phase 1 will enroll 10 patients to assess the safety, tolerability, and pharmacokinetics of single escalating doses over a 30-60 day period. The dose-escalation period will be preceded by a 2-week run in period and followed by a 2-week wash-out period. Phase 2 follow the safe completion of Phase 1. It will enroll 40 patients and is composed of 4 periods of study: 1) a 2-week run-in period, 2) a 3-5 week escalating dose period to identify a prokinetic dose in the initial set of 10 patients, 3) a 1-week period of randomized dosing (placebo versus the previously identified pro-kinetic dose), and 4) a 2-week wash-out period. Pharmacodynamics will be assessed along with safety and tolerability. Relative outcomes will be compared within each patient and across groups for the randomized dosing period. Frequency of bowel movements and other non-motor symptoms of Parkinson's Disease will be collected over the course of both phases.