CSU: Remibrutinib provides rapid clinical benefit

Pooled phase 3 data show that remibrutinib provides rapid and sustained relief in chronic spontaneous urticaria (CSU). Safety data up to week 24 also indicate a favourable profile.

A post-hoc analysis of pooled phase 3 data evaluating remibrutinib as add-on therapy in adults with CSU (≥6 months’ duration) and an inadequate response to second-generation H1-antihistamines was presented by Prof. Ana Giménez-Arnau (Autonomous University and Pompeu Fabra University, Spain) [1]. The analysis focused on daily itch severity scores (ISS) and hives severity scores (HSS) from the REMIX-1 (NCT05030311) and REMIX-2 (NCT05032157) trials. To better characterise the timing of symptom onset, average daily ISS and HSS (including a 12-hour assessment at the end of day 1) were evaluated. ISS ranges from 0 (no itch) to 3 (severe itch), and HSS from 0 (no hives) to 3 (>12 hives).

REMIX-1 and REMIX-2 included a total of 613 patients treated with remibrutinib 25 mg twice daily and 312 receiving placebo. The double-blind period lasted 24 weeks. At baseline, the mean ages were 45.0 and 41.7 years across the 2 trials; severe CSU was present in 63.4% and 59.1% of patients; and the mean disease durations were 6.7 and 5.2 years, respectively [2].

Mean daily HSS scores in the remibrutinib and placebo groups decreased from 2.32 and 2.25 at baseline (day -1) to 2.10 in both groups after 12 hours. A clear difference in favour of remibrutinib by day 2 (HSS 1.60 vs 2.06) [1]. This separation continued to day 7 with HSS of 1.11 and 1.87, respectively. Comparable trends were observed for ISS: baseline scores were 2.12 and 2.04; after 12 hours, 1.86 and 1.89; at day 2, 1.49 versus 1.86; and at day 7, 1.13 versus 1.63, respectively.

An additional perspective was provided by the distribution across severity bands. At baseline, HSS=0 was observed in 1.2% of remibrutinib-treated patients and 0.7% of those receiving placebo; by 12 hours, this increased to 5.8% and 2.4%, respectively. Similarly, ISS=0 was present in <1% of patients in both groups at baseline, increasing to 5.1% with remibrutinib and 2.7% with placebo after 12 hours.

Pooled safety data were comparable between remibrutinib and placebo, with adverse events (AEs) reported in 64.9% and 64.7% of patients, serious AEs in 3.3% and 2.3%, and treatment discontinuation due to AEs in 2.8% and 2.9%, respectively.

The findings are consistent with previously reported long-term data, supporting rapid and sustained improvement in disease activity with remibrutinib, alongside a favourable safety profile.

Mosnaim G, et al. Early symptom improvement with remibrutinib in chronic spontaneous urticaria: Daily Itch Severity Scores and Hives Severity Scores from Phase III REMIX I/II studies. Poster ID 71668. AAD 2026, 27–31 March, Denver, CO, USA.
Metz M, et al. N Engl J Med. 2025;392(10):984-994.