The discovery and profile of PF-0868087, a CNS-sparing histamine H3 receptor antagonist for the treatment of allergic rhinitis

We wished to identify a CNS-sparing histamine H3 receptor antagonist for the treatment of allergic rhinitis. We aimed for compounds with low permeability, high solubility, that were substrates for the BBB efflux transporters MDR-1 and BCRP. The key lead PF-0868087 demonstrated over a 10-fold CNS-sparing profile in 2 preclinical species.