Omalizumab Retreatment and Step-Up in Patients with Chronic Spontaneous Urticaria: OPTIMA Trial

Abstract Background Omalizumab shows greater clinical benefit with 300mg dose than 150mg. Objective To determine outcomes post-withdrawal, relapse, and retreatment in omalizumab responders, and, from stepping up to 300 mg after insufficient symptom control with 150mg. Methods This was a prospective, randomized (3:4), open-label, non-comparator study (clinicaltrials.gov:NCT02161562). 314 adult patients with chronic spontaneous/idiopathic urticaria (CSU) and symptomatic on H1-antihistamines were enrolled between August 1, 2014 and November 6, 2015. Patients received 150mg/300mg 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 UAS7 was >6. If patients relapsed after treatment withdrawal at week 24, they could be retreated with the same dose on which omalizumab was started. Patients on 300mg could extend treatment by 12 weeks if they didn't achieve symptom control on 300mg in the initial dosing phase. Primary endpoint was the proportion of well-controlled patients who relapsed post-withdrawal, and achieved symptom control at the end of retreatment. Symptom control was assessed using the 7-day sum of daily Urticaria Activity Score (UAS7; UAS7 ≤6 = well-controlled). Results Overall, 115/314 patients had adequate symptom control at week 24 (end of initial dosing period), 56 were retreated after relapse post-withdrawal; 87.8% (95% confidence interval [CI] 78.6% to 96.9%) regained symptomatic control (UAS7 ≤ 6). Most (141/178) patients initially treated with 150mg required step-up to 300mg, which resulted in a 9.5 point (95% CI 7.6 to 11.3) improvement in UAS7 scores over the mean change observed initially on 150mg. Conclusion Step-up to 300mg helps a greater proportion of patients achieve symptom control, and retreatment with omalizumab is as effective as initial therapy.