Remibrutinib improves sleep, daily activities in patients with CSU

Treatment with remibrutinib, an oral, highly selective Bruton’s tyrosine kinase inhibitor, improved sleep and daily activities in patients with chronic spontaneous urticaria (CSU), according to two phase III REMIX-1 and -2 studies presented at AAD 2025.

“The symptoms of CSU can be debilitating and adversely affect patients’ sleep and daily activities, … and reduction in CSU disease activity has been shown to alleviate sleep and daily activity interference,” said Dr Robert Snyder from Riverchase Dermatology, Pembroke Pines, Florida, US.

The researchers conducted two identical, multicentre, phase III studies involving 470 (REMIX-1) and 455 patients (REMIX-2) with CSU. These patients were randomized 2:1 to receive either remibrutinib 25 mg twice daily (n=313 [REMIX-1]) and n=300 [REMIX-2]) or placebo (n=157 and n=155, respectively) for a 24-week double-blind treatment period, followed by a 28-week open-label treatment period. At week 24, all placebo recipients were switched to remibrutinib (placebo-transitioned remibrutinib arm). [AAD 2025, abstract 62278]

The weekly Sleep Interference Score (SIS7) and Activity Interference Score (AIS7) were used to determine the effect of remibrutinib on sleep and daily activities in this patient population.

In terms of sleep outcome, a higher percentage of patients treated with remibrutinib achieved a complete absence of sleep interference (SIS7=0) at week 24 compared with placebo in REMIX-1 (58.9 percent vs 44.2 percent) and REMIX-2 (58.2 percent vs 41.2 percent).

By week 52, the proportion of patients experiencing undisturbed sleep (SIS7=0) in both studies was similar between those who initially received remibrutinib and those who were transitioned from placebo to remibrutinib (60.6 percent vs 69.6 percent [REMIX-1] and 64.7 percent vs 62.9 percent [REMIX-2]).

“There was a rapid response in terms of differentiating the improvement in sleep deprivation between remibrutinib and placebo as early as week 1, with progressive improvement through week 24, and a high level of response of no impact [of CSU] on sleep and daily activity, which is what we strived for with treatment, that was maintained through week 52,” said Snyder.

In terms of daily activities, more than half of the participants in the remibrutinib group achieved a complete absence of activity interference or no impact of CSU daily activities (AIS7=0) at week 24 relative to those in the placebo group across both studies (REMIX-1: 55.8 percent vs 42.1 percent and REMIX-2: 53.4 percent vs 32.8 percent).

Patients who transitioned to remibrutinib from placebo and those who received remibrutinib initially showed similar improvements in terms of achievement of AIS7=0 at week 52 (57 percent vs 62.5 percent [REMIX-1] and 62.8 percent vs 60.7 percent [REMIX-2]).

“In both REMIX studies, remibrutinib treatment led to a complete absence of sleep and daily activity interference in a greater proportion of patients (approximately 60 percent) vs placebo (approximately 40 percent), through week 24. These effects were maintained through week 52 in both the remibrutinib and placebo-transitioned remibrutinib arms,” said Snyder.