Omalizumab therapy for chronic spontaneous urticaria: the Israeli experience.

BACKGROUND:
Chronic spontaneous urticaria (CSU) is a common, debilitating disease that is frequently resistant to standard therapy. Omalizumab, anti-immunoglobulin-E humanized monclonal antibody, was recently shown to be effective in treating resistant CSU.

OBJECTIVES:
To investigated the treatment of CSU with omalizumab in Israel.

METHODS:
We conducted a multicenter retrospective analysis of patients with refractory CSU treated with omalizuamb in Israel during 2012-2013. Complete improvement was defined as resolution of symptoms with no need for other medications, or satisfactory when patients' condition improved but required regular or intermittent doses of antihistamines.

RESULTS:
Forty-three patients received omalizumab off-label for refractory CSU. Their mean age was 45 +/- 12 years and CSU duration was 4.3 +/- 4 years. In this cohort, 98% were unsuccessfully treated with high dose H(1)-antihistamines, 88% with systemic glucocorticoids and 30% with cyclosporine and/ or other immune-modulators. Fourteen patients received only one injection of omalizumab, while the other 29 received on average of 4.3 +/- 3.2 injections; 30 patients received 150 mg/ month and 13 received 300 mg/month. Following omalizumab therapy, disease remitted within weeks in 86% of patients, of whom half achieved complete remission. The latter was associated with usage of high dose omalizumab, 300 mg/month vs. 150 mg/month (P = 0.02) and repeated therapy (i.e., multiple injections vs. a single injection) (P = 0.0005).

CONCLUSIONS:
Omalizumab is an effective and safe treatment for refractory CSU with rapid onset of action for inducing and maintaining remission. Treating CSU patients mandates an individual approach, because while low dose omalizumab will suffice for some patients others might need higher doses and prolonged therapy.