• Solengepras 150 mg achieved a statistically significant reduction in daily OFF time, with benefit seen at Week 2
• Statistically significant improvements in secondary endpoints of ON time without troublesome dyskinesia and motor experiences of daily living (MDS-UPDRS Part II)
• Improvements in daytime sleepiness (Epworth Sleepiness Scale) and quality of life (PDQ-39, exploratory) point to broad motor and non-motor benefit
• Generally well tolerated, with fewer adverse events than those typically associated with dopaminergic adjunctive therapies, and a discontinuation rate similar to placebo
• Cerevance to meet with FDA to discuss the path to a potential New Drug Application

Cerevance, a clinical-stage biopharmaceutical company advancing targeted therapies for neurodegenerative diseases, announced positive topline results from ARISE, its randomized, double-blind, placebo-controlled Phase 3 trial of once-daily oral solengepras as an adjunctive treatment for people with Parkinson’s disease experiencing motor fluctuations on levodopa and other Parkinson’s medications. Solengepras is a potential first-in-class therapy that targets the striatal indirect pathway through a novel receptor (GPR6) and has no direct impact on dopamine receptors. The ARISE results support its potential to address both motor and non-motor symptoms of Parkinson’s disease.

Solengepras 150 mg met the trial’s primary endpoint, reducing average daily OFF time by 0.61 hours versus placebo at Week 12 (p=0.0350; 1.56 hours from baseline, compared with 0.95 hours with placebo). The reduction in OFF time versus placebo was seen as early as Week 2, the first post-baseline assessment (0.75 hours; nominal p=0.0022), and at each subsequent visit through Week 12. On the key secondary endpoint, solengepras 150 mg also increased ON time without troublesome dyskinesia by 0.60 hours (p=0.0468; 1.58 hours from baseline, compared with 0.98 hours with placebo).

Participants receiving solengepras 150 mg also showed statistically significant improvement in motor experiences of daily living and improvements on two non-motor measures. On experiences of daily living, a pre-specified secondary endpoint, as measured by the MDS-UPDRS Part II, there was a placebo-adjusted difference of 1.91 points (p=0.0008; 2.05 points from baseline, compared with 0.14 points with placebo). On the Epworth Sleepiness Scale, a secondary measure, daytime sleepiness improved by 0.98 points versus placebo (nominal p=0.009; 1.39 points from baseline, compared with 0.41 points with placebo). On the PDQ-39, an exploratory measure, which measures the impact of Parkinson’s disease on mobility, emotional well-being, communication, and relationships, quality of life improved by 2.87 points versus placebo (nominal p=0.012; 3.73 points from baseline, compared with 0.86 points with placebo).

“In ARISE, patients receiving solengepras spent less time “OFF” and also reported improvements in everyday functioning. Improvements were also observed in quality of life and daytime alertness,” said Robert A. Hauser, M.D., M.B.A., trial investigator and director, Parkinson’s Disease and Movement Disorder Center, University of South Florida; Professor of Neurology, University of South Florida College of Medicine. “OFF time has long been the main way we assess add-on therapies, but it captures only one aspect of the disease. Looking at these measures together may give a fuller picture of a treatment's potential benefits for patients.”

Solengepras was generally well tolerated, and most adverse events were mild or moderate. Discontinuation because of an adverse event was 3.5% in all three arms, including placebo. No serious adverse events were reported with solengepras 150 mg, compared with 1.8% with 75 mg and 0.9% with placebo. Dyskinesia was reported in 4.4% of participants receiving solengepras 150 mg, compared with 1.8% receiving placebo. The most frequently reported adverse events with solengepras 150 mg were headache (8.0% vs 3.5% placebo) and urinary tract infection (8.0% vs 6.1%), followed by insomnia (6.2% vs 0.9%) and nausea (6.2% vs 1.8%). The paucity of typical dopaminergic adverse events may be consistent with the novel mechanism of action of solengepras.

ARISE randomized 341 participants 1:1:1 to once-daily solengepras 75 mg (n=114), solengepras 150 mg (n=113), or placebo (n=114) for 12 weeks. At baseline, participants had an average of 5.65 hours of daily OFF time despite their usual Parkinson’s disease treatments, which all participants continued throughout the trial, and 311 of 341 participants (91%) completed the trial.

“ARISE met its primary endpoint and showed a consistent pattern of benefit across OFF time, ON time, daily motor function, daytime alertness and quality of life, together with favorable tolerability," said Craig Thompson, chief executive officer of Cerevance. "Daily function, alertness, and quality of life are measures that reflect how people with Parkinson's experience their day. As a potential first-in-class, non-dopaminergic therapy, solengepras gives us the opportunity to evaluate what a new mechanism may offer people with Parkinson’s and ARISE was designed to capture that full picture. We look forward to discussing these results with the FDA to determine next steps."

The data were presented by Robert A. Hauser, M.D., M.B.A. and Karl Kieburtz, M.D., M.P.H, chief medical officer of Cerevance, during the 2026 International Congress of Parkinson's Disease and Movement Disorders (MDS) in Seoul, Korea.