RESUMO
BACKGROUND: Omalizumab shows greater clinical benefit with 300 mg dose than with the 150 mg dose. OBJECTIVE: To determine outcomes postwithdrawal, relapse, and re-treatment in omalizumab responders, and from stepping up to 300 mg after insufficient symptom control with 150 mg. METHODS: This was a prospective, randomized (3:4), open-label, noncomparator study (clinicaltrials.gov: NCT02161562). A total of 314 adult patients with chronic spontaneous urticaria and symptomatic on H1-antihistamines were enrolled between August 1, 2014, and November 6, 2015. Patients received 150 mg/300 mg omalizumab, every 4 weeks for 24 weeks. Omalizumab 150 mg dose could be stepped up to 300 mg between week 8 and week 24, if the 7-day sum of the daily Urticaria Activity Score (UAS7) was more than 6. If patients relapsed after treatment withdrawal at week 24, they could be re-treated with the same dose on which omalizumab was started. Patients on 300 mg could extend treatment by 12 weeks if they did not achieve symptom control on 300 mg in the initial dosing phase. The primary end point was the proportion of well-controlled patients who relapsed postwithdrawal, and achieved symptom control at the end of re-treatment. Symptom control was assessed using UAS7 (UAS7 ≤ 6 = well controlled). RESULTS: Overall, 115 of 314 patients had adequate symptom control at week 24 (end of the initial dosing period) and 56 were re-treated after relapse postwithdrawal; 87.8% (95% CI, 78.6%-96.9%) regained symptomatic control (UAS7 ≤ 6). Most (141 of 178) patients initially treated with 150 mg required step-up to 300 mg, which resulted in a 9.5-point (95% CI, 7.6-11.3) improvement in UAS7 over the mean change observed initially on 150 mg. CONCLUSIONS: Step-up to 300 mg helps a greater proportion of patients achieve symptom control, and re-treatment with omalizumab is as effective as initial therapy.