Cerevance’s attempt to unlock the first-line Parkinson's disease market has hit a snag, with solengepras performing no better than placebo in phase 2 when given to people with early, untreated symptoms.
Boston-based Cerevance initially took solengepras, a GPR6 inverse agonist, into phase 2 as an adjunctive treatment to levodopa in Parkinson’s patients experiencing motor fluctuations. People who received the study drug had more daily time without symptoms, encouraging the biotech to start a phase 3 trial in the adjunctive setting and a midstage monotherapy study in early, untreated Parkinson's.
Cerevance reported data from the phase 2 monotherapy study Tuesday. Solengepras was statistically no better than placebo on the MDS-UPDRS Parkinson’s clinical rating scale at Week 12, causing the trial to miss its primary endpoint.
The biotech blamed the miss on results for a physician-administered neurological exam, which assesses physical signs of Parkinson’s at a single point in time. Cerevance saw “trends in improvement” on two patient-reported parts of the MDS-UPDRS endpoint but they fell short of statistical significance. Similarly, motor symptom and sleepiness endpoints favored solengepras without clearing the statistical bar.
Cerevance CEO Craig Thompson said in a statement that the data align with findings from the phase 2 adjunctive therapy trial, with both studies demonstrating benefits on patient-reported measures. As the CEO sees things, the latest data reinforces that solengepras “appears to be more effective in impacting the functional and non-motor symptoms captured by patient-reported outcomes.”
The primary endpoint of the phase 3 adjunctive therapy trial is looking at motor symptoms as reported in patient diaries. Several of the secondary endpoints also capture patient-reported measures. As such, Thompson’s reading of the phase 2 trial manages to frame the failure in a positive light for the phase 3.
Whether Thompson’s positivity is justified could become clearer in the first half of next year, when the biotech expects to report topline data from the phase 3 study. The failed phase 2 trial was free from safety red flags, with all patients in the treatment arm completing the study and no participants experiencing serious adverse events related to solengepras.