CVXL-0107

CVXL-0107 a glutamate release inhibitor, has shown evidence of antiparkinsonian and antidyskinetic activity in a macaque model and has shown a significant effect on the UPDRS-III (Movement Disorder Society - Unified Parkinson's Disease Rating Scale) while "ON", as well as an increase of "ON-time" without dyskinesia or without troublesome dyskinesia in a previous phase 2a proof of concept study. This study will confirm the efficacy of CVXL-0107 in combination with optimal dose of levodopa on motor symptoms of Parkinson's disease (PD) .