Sense and sensibility
Blocking a single receptor could provide relief for multiple asthma symptoms
While bronchodilators and steroids have long been the mainstays of asthma treatment, the dogma has been that the two classes of drugs address distinct processes, airway constriction and inflammation. That hypothesis might be turned on its head by a finding from a U.K. team that shows the calcium sensing receptor acts in a pivotal role in both processes, and opens the door to using a single agent - a CaSR antagonist - to shut down both pathways.
The idea might not need to wait long to be tested. Several CaSR antagonists have already been investigated in at least Phase I trials, primarily for osteoporosis, and found to be safe and well tolerated, although they had low efficacy.
Shire plc has the CaSR antagonist SHP635 (NPSP795) in Phase II for autosomal dominant hypocalcemia. Shire's NPS Pharmaceuticals Inc. subsidiary and GlaxosmithKline plc tested a different CaSR antagonist, ronacaleret, in Phase II trials for osteoporosis in 2008. The compound raised serum calcium levels but missed the