Addex Therapeutics , a leading company pioneering allosteric modulation-based drug discovery and development, announced approval by the ethics committee of the Johns Hopkins University to conduct a receptor occupancy study with dipraglurant in healthy volunteers. The lead investigator for the study is Dean F. Wong, MD, of the Departments of Radiology, Psychiatry and Neuroscience at Johns Hopkins University and the study will be conducted in collaboration with Lorena Gapasin, RN, CCRP; Hiroto Kuwabara, MD, and Anil Mathur, MD, CCRP. The study is supported by a grant from The Michael J. Fox Foundation for Parkinson's Research (MJFF).

Dipraglurant a novel, small molecule inhibitor of the metabotropic glutamate receptor 5 (mGluR5) has successfully completed phase 2 proof of concept in Parkinson's disease (PD) patients suffering from debilitating levodopa-induced dyskinesia (LID). The data from the phase 2 study showed that dipraglurant exhibits a good safety and tolerability profile in PD patients. Dipraglurant also demonstrated a significant reduction in severity of both components of LID (chorea and dystonia) with both 50mg and 100mg doses. The objectives of the current study are to quantify the brain mGlu5 receptor occupancy by positron emission tomography (PET) following single oral dosing of dipraglurant in healthy subjects and to assess the relationship between dipraglurant plasma concentration and brain mGlu5 receptor occupancy. The results of this study will support the design of the phase 2B study, which is currently being prepared.

"Dipraglurant has demonstrated robust phase 2 efficacy in PD LID and along with data from preclinical models of motor and non-motor symptoms leads us to believe that dipraglurant has the potential to provide significant symptomatic relief to Parkinson's patients," says Sonia Poli, chief scientific officer of Addex. "We are excited to be restarting the development of dipraglurant with this important study and look forward to rapidly moving into phase 2B."

"Dr Dean F. Wong and his colleagues at the Johns Hopkins University are some of the world's leading experts in brain imaging and we are proud to have the opportunity to work with them on this important study in the development of dipraglurant," says Tim Dyer, chief executive officer of Addex. "The support of MJFF demonstrates the importance of dipraglurant as a potential treatment for Parkinson's disease levodopa induced dyskinesia."

"The development of treatments to prevent or ease dyskinesia remains a priority for our Foundation," says Todd Sherer, chief executive officer of The Michael J. Fox Foundation. "Innovative therapies against this common side effect hold great potential for improved quality of life for the millions living with Parkinson's disease".

Dipraglurant is an oral, small molecule allosteric modulator that inhibits selectively the metabotropic glutamate receptor 5 (mGluR5), a Class C G-Protein Coupled Receptor (GPCR), with potential to be used in combination with levodopa or dopamine agonists or as a standalone treatment for Parkinson's disease levodopa-induced dyskinesia (PD-LID), motor and non-motor symptoms of Parkinson's disease and other movement disorders. In a double-blind, placebo-controlled, US and European phase 2 study in PD-LID, data showed that dipraglurant met the primary objective of the study by exhibiting a good safety and tolerability profile. Dipraglurant also demonstrated a statistically significant reduction in LID severity with both 50 and 100 mg doses. Dipraglurant reduced dystonia severity in addition to chorea, the two major LID components. Efficacy was measured using the modified Abnormal Involuntary Movement Scale (mAIMS), patient diaries documenting "off-time" (impaired voluntary movement), "on-time" (with or without dyskinesia) and sleep. Additional endpoints include the Unified Parkinson's Disease Rating Scale (UPDRS), the Clinician & Patient Global Impression of Change (CGIC & PGIC), and an evaluation of the patients' mood using the Hospital Anxiety & Depression Score. The trial was supported by a grant from The Michael J. Fox Foundation for Parkinson's Research.

As the world's largest nonprofit funder of Parkinson's research, The Michael J. Fox Foundation is dedicated to accelerating a cure for Parkinson's disease and improved therapies for those living with the condition today. The Foundation pursues its goals through an aggressively funded, highly targeted research programme coupled with active global engagement of scientists, Parkinson's patients, business leaders, clinical trial participants, donors and volunteers. In addition to funding more than $450 million in research to date, the Foundation has fundamentally altered the trajectory of progress toward a cure. Operating at the hub of worldwide Parkinson's research, the Foundation forges groundbreaking collaborations with industry leaders, academic scientists and government research funders; increases the flow of participants into Parkinson's disease clinical trials with its online tool, Fox Trial Finder; promotes Parkinson's awareness through high-profile advocacy, events and outreach; and coordinates the grassroots involvement of thousands of Team Fox members around the world.