The approved dose of omalizumab in this setting is 300mg by subcutaneous injection every 4 weeks. The need for continued therapy should be reassessed periodically. Only the 150mg pre-filled syringe is currently licensed for this indication.
'New option for difficult-to-treat patients'
Dr Tony Bewley, Consultant Dermatologist at Barts Health NHS Trust, London, states that omalizumab "has real potential to revolutionise the treatment of patients with CSU which has not responded to conventional treatment" and "provides clinicians with a new and much needed option to help effectively manage difficult-to-treat patients."
Omalizumab binds to IgE, lowers free IgE levels and leads to downregulation of IgE receptors. It is not entirely understood how this results in an improvement of CSU symptoms.1
The safety and efficacy of omalizumab were assessed in two phase III studies in patients with CSU who remained symptomatic despite treatment with H1 antihistamines at licensed doses.1
In the first study at week 12, omalizumab 300mg reduced weekly itch score (primary endpoint) by 9.4 compared with a reduction of 3.6 in the placebo group.1
Consistent observations were made in the second study for omalizumab 300mg, with a reduction in weekly itch-severity score of 9.8±6.0 compared with 5.1±5.6 in the placebo group (p<0.001).2
The results were similar in a third study which examined the safety of omalizumab in patients with CSU who remained symptomatic despite treatment with H1 antihistamines at up to four times the approved dose plus a H2 antihistamine and/or leukotriene receptor antagonist.3
The most common side-effects were sinusitis, headache, arthralgia and injection site reactions.1
Both presentations of omalizumab are indicated as add-on therapy in severe persistent allergic IgE-mediated asthma.
- Xolair Summary of Product Characteristic, February 2014.
- Maurer M et all. N Engl J Med 2013; 368: 924−35.
- Kaplan A et al. J Allergy Clin Immunol 2013; 132: 101−9.
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Further information: Novartis