PF4455242 hydrochloride

Biological Activity

PF-4455242 is a selective k opioid receptor (KOR) antagonist with 20-fold selectivity for kappa over mu receptors (k Ki = 3 nM, μ Ki =64 nM). PF-4455242 is orally active, has good brain penetration in rats and was able to block the effects of the kappa agonist U50488. Studies indicate th at k blockade has afforded antidepressant activity in several animal models. PF-4455242 has been in phase I clinical trials for trial for bipolar depression.