FDA Approves Remibrutinib for Chronic Spontaneous Urticaria

The FDA today approved remibrutinib (Rhapsido; Novartis), a highly selective Bruton tyrosine kinase inhibitor (BTKi), for the treatment of chronic spontaneous urticaria (CSU) in patients who remain symptomatic despite treatment with H1 antihistamine therapy.¹ The approval marks the first for a BTKi in CSU.

The approval was supported by data from the phase 3 REMIX-1 (NCT05030311) and REMIX-2 (NCT05032157) clinical trials, in which remibrutinib showed more significant changes from baseline in itch, hives, and weekly urticaria activity vs a placebo after 12 weeks of treatment. Those who received remibrutinib were also more likely to achieve well-controlled disease (defined as Urticaria Activity Score 7 of 6 or lower) by week 12 vs those given a placebo (49.8% vs 24.8% in REMIX-1 [P < .001] and 46.8% vs 19.6% in REMIX-2 [P < .001]), with well-controlled disease seen as soon as week 2.² The efficacy appeared to be maintained through week 24.

“CSU is a serious disease that can cause debilitating symptoms and unpredictable flares. It’s difficult to diagnose and manage,” Mark Lebwohl, MD, dean for Clinical Therapeutics at the Icahn School of Medicine at Mount Sinai and member of the steering committee for the remibrutinib REMIX phase 3 clinical trial program, said in a statement.¹ “Remibrutinib represents a new way of treating CSU. By blocking the activity of BTK, remibrutinib stops a key pathway of the immune response in CSU. This is an exciting new option that has the potential to help a broad range of patients get fast relief.”

Remibrutinib was found tolerable, with similar percentages of patients with any adverse event and with serious adverse events in the remibrutinib group and placebo group.² However, a higher percentage of patients in the remibrutinib group had petechiae (3.8% vs. 0.3% in the combined groups). The most common adverse events in the remibrutinib group were COVID-19 (10.7% of patients vs 11.4%), nasopharyngitis (6.6% vs 4.6%), headache (6.3% vs 6.2%), petechiae (3.8% vs 0.3%), urinary tract infection (3.1% vs 2.6%), and urticaria (2.5% vs 4.9%). Notably, remibrutinib requires no lab monitoring.¹

“The approval of remibrutinib is an important development in CSU care," said Giselle Mosnaim, MD, MS, an allergist and immunologist from Endeavor Health, clinical associate professor at the University of Chicago Pritzker School of Medicine, and REMIX trial investigator. "It quickly reduces symptoms, offering patients control of the hives and itching that they experience on a daily basis. This is significant because it expands beyond existing injectable treatments and gives patients an oral option that can easily be incorporated into their daily lives.”

References

1. Novartis receives FDA approval for Rhapsido (remibrutinib), the only oral, targeted BTKi treatment for chronic spontaneous urticaria (CSU). News release. Novartis. September 30, 2025. Accessed September 30, 2025. https://www.novartis.com/news/media-releases/novartis-receives-fda-approval-rhapsido-remibrutinib-only-oral-targeted-btki-treatment-chronic-spontaneous-urticaria-csu

2. Metz M, Giménez-Arnau A, Hide M, et al. Remibrutinib in chronic spontaneous urticaria. N Engl J Med. 2025;392(10):984-994. doi:10.1056/NEJMoa2408792