PF-4455242
PF-4455242
Chemical compound
PF-4455242 is a selective, short-acting (non-"inactivating") antagonist of the κ-opioid receptor.[1][2] Discovered by Pfizer in 2009, it was pursued in a phase I clinical trial for the treatment of bipolar disorder,[3] and was also investigated as a treatment for depression and substance abuse.[4] However, development was stopped in September 2010 due to toxicology findings in animals that had been exposed to the drug for three months.[3]