Scaffold-hopping with zwitterionic CCR3 antagonists: identification and optimisation of a series with good potency and pharmacokinetics leading to the discovery of AZ12436092.

The discovery and optimisation of a series of zwitterionic CCR3 antagonists is described. Optimisation of the structure led to AZ12436092, a compound with excellent selectivity over activity at hERG and outstanding pharmacokinetics in preclinical species.

The discovery of CCR3/H1 dual antagonists with reduced hERG risk.

A series of dual CCR3/H(1) antagonists based on a bispiperidine scaffold were discovered. Introduction of an acidic group overcame hERG liability. Bioavailability was optimised by modulation of physico-chemical properties and physical form to deliver a compound suitable for clinical evaluation.