Efficacy and safety of omalizumab for the treatment of refractory chronic spontaneous urticaria in Japanese patients: Subgroup analysis of the phase 3 POLARIS study

Abstract Background Omalizumab, a humanized anti-IgE monoclonal antibody, proved efficacious and well tolerated in patients with chronic spontaneous urticaria (CSU) refractory to H 1 antihistamines (H 1 AH) in the POLARIS study ( NCT02329223 ), a randomized, double-blind, placebo-controlled trial in East Asian patients. However, data in Japanese patients, who have specific baseline characteristics (e.g., low angioedema incidence, different background medications) that may impact clinical outcomes, are lacking. This pre-specified analysis presents additional patient-level data over time, pharmacokinetic and pharmacodynamics data for omalizumab and IgE, and efficacy and safety data for omalizumab in Japanese patients. Methods Japanese patients (N = 105) were randomized 1:1:1 to omalizumab 300 mg, 150 mg, or placebo by subcutaneous injection every 4 weeks. Efficacy and safety were assessed primarily based on changes from baseline to Week 12 in weekly itch-severity scores (ISS7) and weekly urticaria activity scores (UAS7), and incidence of adverse events (AEs), respectively. Patient-level UAS7 data over time were also reviewed. Results At Week 12, least squares mean (LSM) changes from baseline in ISS7 were greater with omalizumab vs. placebo (−9.54 and −7.29 for omalizumab 300 mg and 150 mg, respectively, vs. placebo [−5.17]). Corresponding LSM changes from baseline in UAS7 were −21.61 and −15.59 (vs. placebo [−10.88]). Most responders in the omalizumab 300 mg group displayed improvement of disease activity within 2–4 weeks and had well-controlled symptoms during the treatment period. Overall AE incidence was similar across treatment arms. Conclusions This subgroup analysis demonstrated that omalizumab is a well-tolerated, beneficial option for treatment of CSU in H 1 AH-refractory Japanese patients.