CVN424, a GPR6 inverse agonist, for Parkinson’s disease and motor fluctuations: a double-blind, randomized, phase 2 trial

CVN424 is a new type of treatment designed to target specific brain pathways involved in Parkinson's disease symptoms. This study tested the safety and effectiveness of CVN424 as an additional treatment to levodopa, aiming to reduce periods when Parkinson’s medication is less effective (known as "OFF-time"). This study was carefully controlled, with neither the participants nor the researchers knowing who received CVN424 or a placebo. Conducted at 21 U.S. locations, it included people with Parkinson's disease who had stable levodopa doses and experienced at least 2 hours of daily OFF-time. Participants were randomly assigned to take one of two doses of CVN424 (50 mg or 150 mg) or a placebo once daily for 28 days. The main goals were to check for side effects and measure how well CVN424 reduced OFF-time. 141 participants were enrolled, with 127 completing the 28-day treatment. The most common side effects were headaches and nausea, though no serious side effects were linked to CVN424. By the end of the study, those taking 150 mg of CVN424 experienced about 1.6 fewer hours of OFF-time compared to a reduction of 0.5 hours in the placebo group. This reduction was significant, showing potential benefits of CVN424. CVN424 was generally safe and well-tolerated. Although this study was relatively short and included a limited number of participants, the 150 mg dose led to a meaningful reduction in OFF-time. These results suggest CVN424 could be a promising addition to Parkinson's disease treatment.