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Omalizumab at highest dose modestly effective for chronic idiopathic urticaria

Clinical Question:
Is omalizumab an effective treatment for chronic idiopathic urticaria?

Bottom Line:
Omalizumab (Xolair) is a very expensive and modestly effective treatment for chronic idiopathic urticaria. (LOE = 1b)

Maurer M, Rosén K, Hsieh HJ, et al. Omalizumab for the treatment of chronic idiopathic or spontaneous urticaria. N Engl J Med 2013;368(10):924-935.  [PMID:23432142]

Study Design:
Randomized controlled trial (double-blinded)


Outpatient (any)

Chronic idiopathic urticaria is treated with antihistamines, but some patients do not respond. The researchers in this industry-sponsored trial included patients between the ages of 12 and 75 years who had at least 6 months of chronic idiopathic urticaria and moderately severe symptoms during a 2-week run-in period. Patients with a known cause of urticaria or previous treatment with steroids, immunomodulators,or H2 blockers were excluded. The patients were randomized to receive 1 of 3 doses of subcutaneous omalizumab (75 mg, 150 mg, or 300 mg) or matching placebo. They received a dose once every 4 weeks for 12 weeks, followed by a 16-week untreated follow-up period. Patients recorded symptoms daily, and the primary outcome was the change in weekly itch-severity scores on a 21-point scale. Groups were balanced at the start of the study, with a mean age of 43 years, approximately 75% were female, and 88% were white. And the outcomes? The itch-severity score dropped 3 points in the 150-mg dose group and 4.7 points in the 300-mg group, while the 75-mg group did not show significant improvement. A skin-specific quality-of-life index improved slightly for the 150-mg and 300-mg groups compared with placebo. Patients in the 300-mg group took 4 fewer 25-mg diphenhydramine tablets than those in the placebo group. Adverse events were more common in the 300-mg dose group (5 versus 1 or 2 in the other groups; statistical significance not reported). Xolair costs between $500 and $2000 a month, depending on the dose. Since only the higher doses were effective in this study, 3 years of treatment (a typical duration for this condition) would cost $36,000 to $72,000. Those 4 extra diphenhydramine tablets per week are probably a bit cheaper.


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