Current report 17/2024 – Positive Phase II top – line results for CPL’ 36, a PDE10A inhibitor in the treatment of acute schizophrenia

In reference to current report No. 26/2020 of September 30, 2020 on obtaining consent to start a Phase II clinical trial on a drug based on CPL'36, an innovative PDE10A inhibitor in patients with psychotic exacerbation of schizophrenia, the Management Board of Celon Pharma S.A. (the "Company") announces positive Phase II top-line results of CPL’36, for PDE10 selective inhibitor in acute schizophrenia.

This was multinational, multicenter, randomized, placebo controlled study. CPL’36 was administered orally once daily in 20mg and 40 mg fix doses, and compared with placebo (1:1:1) in a total of 189 patients with acute exacerbation of schizophrenia over a period of 4 weeks. The enrolled patients  PANNS total baseline score was 105 , indicating they were moderately to severely ill.

At week 4 the improvement in PANSS total scale  at the dose 20mg  was 9,7 (LS Mean difference from placebo, p<0,001, Cohen’s d: 0,77) and improvement at the dose 40 mg was 16,4 (LS Mean difference from placebo, p<0,001, Cohen’s d: 1,47).

At week 4 the improvement in PANSS Positive subscale, which was primary endpoint  of the study at the dose 20mg  was 3,7 (LS Mean difference from placebo, p<0,001, Cohen’s d: 0,73) and improvement at the dose 40 mg was 6,3 (LS Mean difference from placebo, p<0,001, Cohen’s d: 1,38).

CPL’36 was well tolerated. There were only few treatment emergent serious adverse events (1,5% in placebo group, 1,8% in 20 mg dose and 3,1% in 40 mg dose). Related treatment emergent adverse events leading to discontinuation of study medication were recorded in 3,1% in placebo group, 0% in 20 mg dose and 7,7% in 40 mg dose. A similar number of patients in the placebo and active cohorts discontinued drug administration during the treatment period.

The study met all endpoints, exceeding significantly earlier Company’s medical assumptions. It demonstrated robust and consistent efficacy across all other scales suggesting positive effect of CPL’36 on broad disease  pathophysiology. The effect size was large to very large.

This is the first study in the world demonstrating robust efficacy of PDE10A inhibition in the treatment of schizophrenia with positive primary and secondary endpoints readouts. According to the Company, its results should be seen as breakthrough milestone in schizophrenia pharmacotherapy.

CPL’36 is being developed for psychiatric and neurological disorders with significant impact, including schizophrenia and levodopa-induced dyskinesia (LID) in Parkinson’s disease. Phase 2 top-line results from the LID trial are expected in Q4 2024.