PF-04859989 is a brain-penetrable irreversible inhibitor of kynurenine amino transferase II (KAT II), the enzyme responsible for most of the brain synthesis of kynurenic acid, which has been implicated in several psychiatric and neurological disorders, including schizophrenia and bipolar disorder, and thought to impair cognitive function. PF-04859989 has IC50 values of 23 nM for hKAT II and 263 nM for rKAT II. PF-04859989 is ~1000-fold selective for KAT II over human KAT I, KAT III, and KAT IV. PF-04859989 prevented ketamine-induced disruption of performance in memory tasks in both rodents and nonhuman primates.
