Omalizumab for severe persistent allergic asthma

• omalizumab is a recombinant humanised monoclonal antibody that inhibits the binding of IgE to high affinity receptors (FceRI) on the surface of mast cells and basophils
  • prevents the release of pro-inflammatory mediators and reduces allergen-induced airway reactions
  • licensed as add-on therapy to improve asthma control in adult and adolescent patients (12 years and older) with severe persistent allergic asthma who have a positive skin test or in vitro reactivity to a perennial aeroallergen and who have reduced lung function (forced expiratory volume in 1 second, FEV1 < 80% ) as well as frequent daytime symptoms or night-time awakenings and who have had multiple documented severe asthma exacerbations despite daily high-dose inhaled corticosteroids, plus a long-acting inhaled beta-2 agonist
  • should only be considered for patients with convincing IgE mediated asthma
  • administered subcutaneously every 2-4 weeks
    • dosage is determined by baseline IgE before the start of treatment (measured in international units per millilitre, IU/ml) and body weight (in kg; see the summary of product characteristics (SPC))
  • side effects
    • most common side effects of omalizumab treatment are bruising, erythema and pain at the site of injection
    • rare side effects include increased risk of parasitic infections, anaphylaxis, usually within 2 hours of the first injection and possible drug-induced malignancies
    • note that allergic reactions, including anaphylaxis and anaphylactic shock, may occur beyond 2 hours and sometimes beyond 24 hours of first injection
      • patients should be informed that such reactions are possible and prompt medical attention should be sought if allergic reactions occur
        
        
  • NICE have issued guidance with respect to the use of omalizumab in asthma. Summary points are:
    • omalizumab is recommended as an option for treating severe persistent confirmed allergic IgE-mediated asthma as an add-on to optimised standard therapy in people aged 6 years and older who need continuous or frequent treatment with oral corticosteroids (defined as 4 or more courses in the previous year), and
      • only if the manufacturer makes omalizumab available with the discount agreed in the patient access scheme
    • optimised standard therapy is defined as a full trial of and, if tolerated, documented compliance with inhaled high-dose corticosteroids, long-acting beta2 agonists, leukotriene receptor antagonists, theophyllines, oral corticosteroids, and smoking cessation if clinically appropriate

Australian guidance with respect to monoclonal antibodies (2):

• four monoclonal antibody therapies (benralizumab, mepolizumab, dupilumab and omalizumab) are available in Australia for the treatment of severe asthma in patients whose asthma is uncontrolled despite optimised standard treatment

Key Points

• monoclonal antibody therapy is an add-on treatment option for reducing severe flare-ups and improving symptom control in patients with severe allergic or eosinophilic asthma whose asthma is uncontrolled despite treatment with high-dose inhaled corticosteroids and long-acting beta2 agonists.
• these therapies target inflammatory pathways that activate type 2 immune responses leading to airway inflammation.
• patients using these treatments must keep taking their inhaled corticosteroid-containing preventers.
• after treatment has been initiated by a specialist, ongoing maintenance doses can be administered in primary care, or by the patient or carer, under specialist supervision.
• monoclonal antibody therapies currently available in Australia for severe asthma are generally well tolerated
  • injection site reactions are among the most common adverse events. Systemic reactions, including anaphylaxis, are rare but can occur.
• like all patients with asthma, those using monoclonal antibody therapies need an up-to-date written asthma action plan.

Reference:

• (1) NICE (April 2013).Omalizumab for severe persistent allergic asthma
• (2) National Asthma Council - Australia. Monoclonal antibody therapy for severe asthma (accessed 24th November 2022).