Positive Results For Remibrutinib May Redraw the Lines For Who Takes Care of Patients With Chronic Spontaneous Urticaria | AAD 2025

Chronic spontaneous urticaria (CSU) has been the province of allergists because it was commonly viewed as related to an allergic reaction.

But that may be changing.

“It was thought by both patients and physicians that chronic spontaneous urticaria was an allergic condition, that there was something that the patients who were being exposed to causing it,” Robert A. Snyder, M.D., a dermatologist at Riverchase Dermatology and Cosmetic Surgery in Florida, said in an interview with Managed Healthcare Executive. “But we now know that for more than half of patients, it's an autoallergic or autoimmune condition, which makes it no different than the other autoimmune inflammatory skin conditions that dermatologists treat. I think that's why the specialty is ripe for picking this disorder up and treating it.”

Snyder’s views about the cause of CSU and who should treat are based in part on the positive results that remibrutinib is showing as a treatment for CSU. A Novartis drug, remibrutinib inhibits Bruton’s tyrosine kinase, an enzyme that plays various roles in proinflammatory and autoimmune processes. Findings from two phase 3 trials of remibrutinib, REMIX-1 and REMIX-2, were reported in The New England Journal of Medicine (NEJM) this week that showed the drug was superior to placebo in controlling itching and angioedema in patients with CSU after Patients in the remibrutinib group also experience better sleep and less disruption in their daily from CSU than those who were randomly assigned to the placebo group.

Snyder presented data from the same two trials today at the 2025 meeting of the American Academy of Dermatology that showed that after a year of treatment, 60.6% of the patients in REMIX-1 randomly assigned to take remibrutinib and 64.7% in REMIX-2 had no sleep or activity problems stemming from CSU.

Snyder said the REMIX-1 and REMIX-2 trials showed no significant difference in the adverse events experienced by the patients who were treated with remibrutinib compared with those treated with placebo. The investigators reporting the results in NEJM noted a higher rate of petechiae in the remibrutinib group than in the placebo group (3.8% vs. 0.3%).

CSU is characterized by itch, hives (urticaria is the medical term for hives) and angioedema in various combinations. Snyder said the condition usually affects people between the ages of 20 and 40 and that women are twice as likely to be affected as men. He said that of all the chronic inflammatory skin conditions, CSU is the one that is most likely to resolve. Even so, that would not be a reason for withholding treatment, because the people often live with the condition for years, and “patients with moderate-to-severe CSU have a tremendous burden in terms of the quality of life, so they need treatment. There is no question about that.”

Snyder said he envisions clinicians prescribing remibrutinib after CSU patients don’t respond to second-generation antihistamines at their maximized doses. The authors of the NEJM study wrote that more than 50% of patients continue to have symptoms while receiving antihistamines, and up to 75% continue to have symptoms despite increasing the dose up to four times the standard dose. In Snyder’s opinion, it might be prescribed prior to, or instead of, omaluzamab, which is sold under the brand name Xolair. “I think because of that, it may bring chronic spontaneous urticaria back to dermatology. It's been kind of shunted off to allergy for the most part.” Snyder said remibrutinib should make CSU a disorder that's commonly treated by dermatologists.