Omalizumab Highly Effective for Treatment of Chronic Spontaneous Urticaria

A study in Drug Design, Development, and Therapy provides further evidence that omalizumab is safe and effective for treatment of chronic spontaneous urticaria (CSU). Omalizumab is currently used to treat adult and pediatric patients with asthma and is FDA-approved for use in patients with CSU refractory to antihistamines. These results further outline the effectiveness of the drug in treating CSU and suggest a bump for omalizumab in the typical treatment protocol for CSU.

CSU, often used interchangeably with the term “chronic idiopathic urticaria”, is not particularly common, but it has significantly greater impact on quality of life than acute urticaria. Research has shown that the chronic form of the condition can last more than six weeks. Its exact pathogenesis remains unknown, despite a great deal of clinical investigation. Some combination of mediators such as cytokines and proteases, histamine, and abnormalities in the basophil signal transduction and number are either known or highly suspected to contribute to CSU.

Omalizumab is a recombinant humanized anti-immunoglobulin E (IgE) antibody that binds to the Cε3 domain of the IgE heavy chain. It has been shown to be safe and effective for treatment of asthma and for non-autoimmune urticaria. “The rationale to employ omalizumab for controlling CSU was that the IgE binding with omalizumab causes internalization of the IgE receptor, and as a consequence, the disappearance of the autoantigen,” the study authors noted.

The current study collected data on the efficacy and safety of omalizumab in 110 patients from nine Spanish hospitals suffering from refractory CSU, and found results even better than previously reported in several clinical trials. Ninety (81.8%) patients exhibited a complete or significant response, 12 (10.9%) had partial response, and eight (7.2%) showed no response. Sixty-six (60%) patients were able to stop all concomitant medications, remaining asymptomatic treated with omalizumab alone. No serious AEs were reported.

“We did not find differences when we compared efficacy and time of response among different doses or scheduled protocols, even considering the different types of CSU included in the analysis and subanalysis (CSU with or without associated physical urticaria, CSU with angioedema, and chronic autoimmune urticaria patients),” the authors wrote.

Of the 110 patients included, 41 discontinued use of omalizumab, 21 remained free of symptoms, and 20 required a reintroduction of the treatment. The researchers noted that omalizumab did not lose effectiveness upon reintroduction, and was equally effective again in 18 of the 20 patients in whom the drug was initially withdrawn.

The study authors caution that more late-stage clinical research is needed to determine the patient profile most suitable for omalizumab treatment, the optimal duration of therapy, and rates of long-term remission — as well as any potential long-term side effects.