Cerevance Moves Forward with Phase III Parkinson’s Trial Despite Setback

Biotech company Cerevance is pushing ahead with a critical Phase III trial of its experimental Parkinson’s disease treatment, solengepras, even though the drug failed to show significant benefits in an earlier Phase II study. What Happened in Phase II? The Phase II ASCEND trial, presented at the AD/PD 2025 conference in Vienna, tested solengepras in people with early-stage Parkinson’s. The drug was meant to improve motor symptoms, but the results were disappointing—solengepras did not perform significantly better than a placebo in standard clinical assessments. Despite this, the study did show some positive signs in patient-reported measures. Those taking solengepras experienced small improvements in non-motor symptoms like sleepiness and daily function, suggesting the drug may still have benefits beyond traditional dopamine-based treatments. Why Continue to Phase III? Cerevance remains optimistic about solengepras because, while it didn’t show a clear motor benefit in Phase II, it was well tolerated, and patients reported some improvements in quality of life. The upcoming Phase III ARISE study will focus on a key measure for Parkinson’s patients—reducing daily “OFF” time. OFF time refers to periods when symptoms return despite being on medication. How Does Solengepras Work? Unlike most Parkinson’s treatments that target dopamine levels, solengepras is designed to work differently. It’s an oral therapy that blocks a brain receptor called GPR6, which is thought to play a role in both motor and non-motor symptoms of the disease. If successful, it could offer a new approach to treating Parkinson’s with fewer side effects than traditional dopamine-based therapies. What’s Next? Cerevance will now test solengepras in a larger Phase III study, aiming to confirm whether it can meaningfully improve patients’ daily lives. With the Parkinson’s disease treatment market projected to grow to nearly $8 billion by 2033, there is strong demand for new and better therapies. While the Phase II results were not what Cerevance had hoped for, the company believes solengepras still has potential. The next stage of testing will determine if this experimental drug can fill the treatment gaps that existing therapies leave behind.