Omalizumab, Remibrutinib Show Similar Early CSU Gains in Indirect Analysis

Omalizumab produced early improvements in disease activity vs placebo in chronic spontaneous urticaria (CSU), and these appeared similar to remibrutinib over the first 14 days of treatment in a post hoc indirect comparison presented at the American College of Allergy, Asthma & Immunology (ACAAI) 2026 Annual Scientific Meeting in Phoenix, held November 12 to 16, 2026.¹

Both agents are approved for CSU in patients who remain symptomatic despite H1-antihistamines. Omalizumab is an anti-IgE antibody, and remibrutinib is an oral Bruton's tyrosine kinase inhibitor.¹ Omalizumab response at week 12 is well established, and up to 24% of patients achieve complete response by week 4.^1,4

"Given the impact of CSU on patient quality of life, fast response to treatment is an important consideration," wrote Shyam Joshi, MD, of Oregon Health & Science University, and colleagues.¹

Early omalizumab response vs placebo in ASTERIA I/II

The analysis pooled data from the phase 3 ASTERIA I and II trials. It compared daily urticaria activity scores (UAS; range, 0–6) over the first 14 days in 160 patients receiving omalizumab 300 mg and 159 receiving placebo.^1,3 Mean daily UAS declined more with omalizumab than with placebo across the 14-day period.¹

At week 1, 6% of patients receiving omalizumab achieved a response, defined as a weekly UAS (UAS7) of 6 or less, vs 2% receiving placebo. No patients in either group had a complete response (UAS7 = 0).¹ By week 2, response rates were 39% with omalizumab vs 6% with placebo, and complete response rates were 13% vs 3%.¹

Indirect comparison with remibrutinib in REMIX-1 and REMIX-2

The investigators then used published data from the pooled phase 3 REMIX-1 and REMIX-2 trials of remibrutinib (n = 613) vs placebo (n = 312).^1,2 They compared placebo-adjusted differences in mean daily UAS between the 2 agents using unmatched comparisons and 2-sample t tests.¹

Baseline characteristics were broadly similar across trials. Mean UAS7 was 30.4 in the omalizumab arm vs 30.6 and 30.2 in the remibrutinib arms of REMIX-1 and REMIX-2, and mean Dermatology Life Quality Index scores ranged from 12.9 to 14.2 across all arms.¹ The proportion of female patients was higher in the omalizumab arm (76.9%) than in the remibrutinib arms (67.7% and 65.7%).¹

Placebo-adjusted improvements in mean daily UAS did not differ significantly between omalizumab and remibrutinib at day 2 (P = .52), day 7 (P = .39), or day 14 (P = .15).¹

"By post hoc indirect comparison, improvements in disease activity appeared to be similar for omalizumab vs remibrutinib during the first 14 days post treatment initiation, highlighting that omalizumab remains an effective treatment option for patients with CSU," Joshi and colleagues wrote.¹

The comparison was post hoc and unadjusted, and it drew on trials conducted roughly a decade apart. The study was funded by Genentech, which markets omalizumab, and 3 of the 6 authors are Genentech employees.¹ Safety results for both trial programs have been published previously and were not reanalyzed.¹

References

1. Joshi S, Burg C, Iqbal A, et al. Early improvement in disease activity with omalizumab vs remibrutinib in patients with chronic spontaneous urticaria. Poster 8059. Presented at: American College of Allergy, Asthma & Immunology 2026 Annual Scientific Meeting; November 12-16, 2026; Phoenix, AZ.

2. Metz M, Giménez-Arnau A, Hide M, et al. Remibrutinib in chronic spontaneous urticaria. N Engl J Med. 2025;392:984-994.

3. Maurer M, Rosén K, Hsieh HJ, et al. Omalizumab for the treatment of chronic idiopathic or spontaneous urticaria. N Engl J Med. 2013;368:924-935.

4. Kaplan A, Ferrer M, Bernstein JA, et al. Timing and duration of omalizumab response in patients with chronic idiopathic/spontaneous urticaria. J Allergy Clin Immunol. 2016;137:474-481.