OBJECTIVES : Chronic spontaneous urticaria (CSU) may impair work performance as it affects a young population and is a visible disease. Omalizumab rapidly improved Work Productivity and Activity Impairment (WPAI) scores during the initial open-label period of XTEND‑CIU, a Phase IV randomized study of omalizumab in symptomatic patients with CSU (≥12 years). Here, we compare changes in WPAI scores between omalizumab and placebo during the double-blind period of XTEND-CIU, where placebo patients are taken off omalizumab.

METHODS : Responders from the 24-week open-label period subsequently entered a 24-week randomized, double-blind period (3:2 randomization omalizumab 300 mg subcutaneously every 4 weeks [n=81] or placebo [n=53]), during which patients completed the WPAI (0-100%; high scores indicate high impairment) at Weeks 24, 36, and 48. WPAI is a 6-item patient-reported outcome (PRO) tool that assesses absenteeism and activity/overall work impairment.

RESULTS : Among 134 randomized patients (75% female, median age 46 years), the mean change (95%CI) from Week 24 to Week 48 in WPAI Activity Impairment score with omalizumab (6.6 [1.7, 11.6]) was significantly lower than with placebo (33.0 [22.6, 43.5], P<0.0001). Similarly, the mean change (95%CI) in WPAI Overall Work Impairment percent scale was significantly lower with omalizumab (1.2 [‑2.6, 4.9]) than placebo (24.4 [11.1, 37.6], P=0.0001). The mean change (95%CI) in Work Time Missed from Week 24 to Week 48 was also lower with omalizumab (-0.2% [-1.5, 1.1]) than placebo (1.6% [-6.2, 9.4]). Overall Work Impairment score and Work Time Missed in the omalizumab group were similar at Week 24 and Week 48.

CONCLUSIONS : Omalizumab responders randomized to additional 24-week omalizumab treatment sustained improvements in WPAI scores from Weeks 24 to 48. For placebo patients, who stopped omalizumab at Week 24, WPAI scores increased (worsened) by Week 48. These results highlight the long-term positive impact of omalizumab on work productivity and activity impairment.