Are currently available biomarkers useful to discriminate CSU patients not controlled by low dose omalizumab maintenance therapy?

In patients with Chronic Spontaneous Urticaria (CSU), low dose omalizumab maintenance therapy is effective in about one half of complete, fast responders to the drug. Omalizumab 150 mg/month was given as maintenance therapy to 21 patients with a history of severe CSU showing a complete (UAS7=0) response to the dose of 300 mg/month. After 2 months of such regimen, patients were divided into controlled (n=14; UAS7=0) and not controlled (n=7; UAS7 greater-than 10) and ESR, CRP, total IgE, and D-dimer were measured. The two groups did not differ in any of the biomarkers considered, nor in disease duration or in pre-treatment UAS7 score. The study confirms that it is possible to halve the dose of omalizumab without any loss of efficacy in a subgroup of patients with CSU but that none of the currently available biomarkers is able to predict which patients will lose disease control following omalizumab dose reduction.