Drug Breakdown: Omalizumab

Dr Sharon Rees @reesprescribe

Day 1: Technological advances allowed the development of a humanised anti-IgE monoclonal antibody (MAB) capable of neutralising immunoglobulin E (IgE) action for the management of allergic asthma and chronic urticaria. #omalizumab is 95% human and 5% murine. Licensed by the European Medicines Agency in 2005.

Dr Sharon Rees @reesprescribe

Day 2: #omalizumab is used in people ≥ 6 years old for moderate to severe IgE-mediated allergic asthma, with frequent symptoms/exacerbations despite optimum therapy and proof of one or more aeroallergen. Usually added into other therapies.

Dr Sharon Rees @reesprescribe

Day 3: #omalizumab subcutaneous injection(s) dosing is based on serum IgE levels and body weight (kg); range 75–600 mg every 2–4 weeks. UK license also for idiopathic chronic urticaria ≥12 years 300 mg once/month for 6 months.

Dr Sharon Rees @reesprescribe

Day 4:#omalizumab kinetics; subcutaneous injection gives moderate absorption (1 week to cmax) and 62% bioavailability. Breakdown is via IgE clearance processes ie recycled and degraded by liver phagocytic cells (reticuloendothelial system) and endothelial cells. T½ 24–26 days, so can take 12–16 weeks to work. Check efficacy at this point.