Mepolizumab is in development for the treatment of chronic rhinosinusitis with polyposis (polyps) (CRSwNP). Nasal polyps are characterised by oedema (swelling) and accumulation of a type of white blood cell called eosinophils. Nasal polyps cause symptoms such as nasal blockage, loss of smell and rhinorrhoea (frequent runny nose). The cause of CRSwNP is not completely understood, however, it is more common in people with other conditions including asthma. In addition, CRSwNP has been linked to having high levels of a protein called IL-5, which interacts with eosinophils and promotes their development.
Mepolizumab is an antibody that binds to IL-5 to prevent it from interacting with its receptor on the surface of eosinophils. This binding prevents their maturation, differentiation, mobilisation, activation and survival; thereby controls their activity. Mepolziumab is administered subcutaneously. If licenced, mepolizumab will offer an additional treatment option –on top of standard care – for patients with CRSwNP, who frequently suffer from uncontrolled symptoms and disease recurrence.