Cerevance reported positive topline results from its Phase 3 ARISE trial, showing that its oral investigational therapy solengepras reduced motor fluctuations in people with Parkinson’s disease who were already receiving levodopa and other Parkinson’s medications. The study evaluated solengepras as an add-on treatment in patients experiencing periods when the effects of their medication wear off, and symptoms return, known as OFF time.
The randomized, double-blind, placebo-controlled trial enrolled 341 participants who were assigned to receive either 75 mg of solengepras, 150 mg of solengepras, or placebo once daily for 12 weeks. The study’s primary endpoint was met by the 150 mg dose, which reduced average daily OFF time by 0.61 hours compared with placebo at Week 12. Improvements were observed as early as Week 2 and continued through the remainder of the trial.
The higher dose also increased ON time without troublesome dyskinesia by 0.60 hours compared with placebo at Week 12.
Improvements in Daily Function and Non-Motor Measures
In addition to the OFF time and ON time findings, participants receiving 150 mg solengepras demonstrated benefits on several measures related to daily functioning and non-motor symptoms.
On the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Part II, which assesses motor experiences of daily living, patients achieved a placebo-adjusted improvement of 1.91 points. The treatment group also showed a 0.98-point improvement in daytime sleepiness on the Epworth Sleepiness Scale.
An exploratory assessment using the Parkinson’s Disease Questionnaire-39 (PDQ-39) found a 2.87-point improvement compared with placebo. The questionnaire measures the impact of Parkinson’s disease on mobility, emotional well-being, communication, and relationships.
“Daily function, alertness, and quality of life are measures that reflect how people with Parkinson’s experience their day,” said Craig Thompson, chief executive officer of Cerevance.
Safety and Tolerability Findings
According to the company, solengepras was generally well tolerated, with most adverse events classified as mild or moderate. Discontinuation due to adverse events was 3.5% across all study groups, including placebo.
No serious adverse events were reported among participants receiving the 150 mg dose. Serious adverse events occurred in 1.8% of participants receiving 75 mg and 0.9% of those receiving placebo.
Dyskinesia was reported in 4.4% of participants treated with 150 mg solengepras, compared with 1.8% in the placebo group. The most commonly reported adverse events in the higher-dose group were headache and urinary tract infection, each reported in 8.0% of participants, followed by insomnia and nausea, both reported in 6.2%.
Of the 341 participants enrolled, 311 completed the study. At the start of the trial, participants experienced an average of 5.65 hours of daily OFF time despite ongoing Parkinson’s disease treatments, which participants continued throughout the trial.
Mechanism, Previous Study and Next Steps
Solengepras is a potential first-in-class therapy that targets the striatal indirect pathway through the GPR6 receptor and has no direct impact on dopamine receptors. Cerevance states that the therapy selectively targets the indirect basal ganglia pathway by inhibiting GPR6 receptors, which are enriched in dopamine-expressing neurons.
The Phase 3 outcome follows a Phase 2 study in April 2025 involving a similar patient population. In that trial, solengepras was statistically no better than placebo on a Parkinson’s disease scale at 12 weeks. At the time, Cerevance attributed the result to findings from a physician-administered neurological examination and also pointed to trends in improvement on two patient-reported parts of the endpoint.
Following the ARISE results, Cerevance said it plans to seek FDA approval for solengepras for Parkinson’s disease and discuss the findings with the agency 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., during the 2026 International Congress of Parkinson’s Disease and Movement Disorders in Seoul, Korea.
Cerevance Reports Positive Phase 3 Results
Cerevance has announced positive results from its Phase 3 ARISE clinical trial evaluating solengepras, an investigational oral treatment for people living with Parkinson’s disease. Announced on October 7, 2026, the results showed that the higher dose met the study’s primary endpoint, marking an important milestone for the company’s neurological drug development program.
The trial evaluated solengepras as an add-on treatment for patients who continue to experience motor fluctuations despite taking levodopa and other standard Parkinson’s medications. These fluctuations can cause periods when medication benefits wear off and symptoms such as stiffness, slowness, and difficulty moving return.
Why the Results Matter for Parkinson’s Treatment
The results could be important because Parkinson’s patients may experience increasingly unpredictable responses to conventional treatments over time. OFF periods can interfere with everyday activities, independence, and quality of life.
Cerevance is exploring whether a non-dopaminergic approach can provide additional symptom control without relying on the same mechanism as standard treatments.
If further development confirms the findings, solengepras could potentially offer another option for patients who continue to experience motor fluctuations despite existing therapy. However, the results do not establish that the medicine is superior to currently available treatments because the ARISE trial compared it with placebo as an add-on therapy, not with another active treatment.
What’s Next for Cerevance?
Following the positive Phase 3 results, Cerevance plans to meet with the U.S. Food and Drug Administration (FDA) to discuss the next steps toward a potential New Drug Application.
