Actelion reaches proof-of-concept in allergic rhinitis
Allschwil – Swiss biotech firm Actelion Pharma has reached the primary endpoint of preventing allergic rhinitis symptoms in patients challenged with Mountain Cedar pollen in a proof-of-concept study with its oral CRTH2 antagonist. According to the company, no severe side effects occurred. Actelion's CRTH2 blocker, which was tested against placebo on 579 patients, inhibits the action of prostaglandin D2 and thus blocks prolongation of allergic symptoms. Because it calms down pro-inflammatory effects, it has also potential to be applied in other blockbuster indications such as allergic asthma. Results of an ongoing Phase II study in this indication are expected by mid-2012, according to Actelion. CRTH2 (Chemoattractant Receptor-homologous molecule expressed on Th2 cells) is a G protein coupled receptor expressed by Th2 lymphocytes, eosinophils, and basophils. The receptor mediates the activation and chemotaxis of these cell types in response to prostaglandin D2 (PGD2), the major prostanoid produced by mast cells. PGD2 is released through mast cell degranulation in the initial phase of IgE-mediated reactions. This process is also thought to occur at the site of inflammation, such as the nasal and bronchial mucosa.