TAK-063 (1-(2-fluoro-4-pyrazol-1-ylphenyl)-5-methoxy-3-(2-phenylpyrazol-3-yl)pyridazin-4-one, MW: 428.427 g/mol) is another PDE10A inhibitor that failed to meet the primary endpoint (PANSS reduction) in a randomized, placebo-controlled six-week phase II trial including 164 patients with stable schizophrenia and residual negative/cognitive symptoms (NCT02477020) but reached statistical significance in CGI score reduction [113]. Here, PDE10A is linked to schizophrenia.