Mepolizumab is a humanised antibody that targets interleukin-5 (IL-5), the major cytokine responsible for eosinophil regulation. Mepolizumab prevents IL-5 from binding to the receptor on the eosinophil cell surface, inhibiting IL-5 signalling and reducing the production and survival of eosinophils.
Three double-blind, randomised controlled trials (, and ) found mepolizumab to be more effective than placebo in reducing the rate of exacerbations in patients with severe asthma. In addition, patients receiving mepolizumab experienced greater reductions in their daily maintenance oral corticosteroid dose than patients receiving placebo, while maintaining asthma control.
Nucala is administered by a healthcare professional via subcutaneous injection into the upper arm, thigh or abdomen every four weeks.
Headaches were reported as the most frequently occurring adverse effect.