Novartis announced FDA approval of Rhapsido (remibrutinib) as an oral treatment for adult patients with chronic spontaneous urticaria (CSU) who remain symptomatic despite H1 antihistamine treatment. CSU is a condition characterized by red, swollen, and itchy hives, and is thought to be caused by immune dysregulation.

According to a company press release, FDA approval was based on findings from the Phase III REMIX-1 and REMIX-2 clinical trials, which evaluated patients with CSU who remained symptomatic on second-generation H1 antihistamines. The study found that significantly more patients treated with remibrutinib achieved well-controlled disease relative to those given placebo. Additionally, about one-third of patients achieved complete absence of itches and hives by Week 12 of the study.

According to the release, CSU can cause certain immune cells to activate the Bruton’s tyrosine kinase (BTK) protein, which is thought to lead to the release of histamine and other proinflammatory mediators that may cause the hives commonly seen in CSU. Remibrutinib functions by inhibiting the BTK protein, and is the first FDA-approved therapy for patients with CSU to do this.

“CSU is a serious disease that can cause debilitating symptoms and unpredictable flares. It’s difficult to diagnose and manage,” said Mark Lebwohl, Dean for Clinical Therapeutics at the Icahn School of Medicine at Mount Sinai and member of the steering committee for the remibrutinib REMIX Phase III clinical trial program, in the release. “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.”

“The approval of remibrutinib is an important development in CSU care. It quickly reduces symptoms, offering patients control of the hives and itching that they experience on a daily basis,” said Giselle Mosnaim, an Allergist and Immunologist from Endeavor Health, Clinical Associate Professor at the University of Chicago Pritzker School of Medicine, and REMIX trial investigator, in the release. “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.”