A potent and selective inhibitor of phosphodiesterase type 10 (PDE10; Ki = 4 nM); has >38-fold selectivity for PDE10 over a panel of 60 CNS-associated receptors, enzymes, and ion channels in vitro; increases striatal cGMP and CREB phosphorylation in vivo; reduces scopolamine- and MK-801-induced memory deficits in rats; inhibits tumor cell growth with IC50 values of 0.29 and 0.22 mM for HCT116 and SW480 colon cancer cells, respectively