Rhapsido (remibrutinib) is an oral selective Bruton tyrosine kinase (BTK) inhibitor approved on September 30, 2025 in the US for the treatment of chronic spontaneous urticaria (CSU) in adult patients who remain symptomatic despite treatment with H1 antihistamines.[3][2] In two phase 3 studies, REMIX-1 and REMIX-2 achieved a significant reduction in UAS7 versus placebo at week 12 (LS mean change in REMIX-2: -19.41 with Rhapsido vs -11.73 with placebo; p<0.001).[1] At week 12, patients achieved UAS7=0 (complete absence of urticaria and pruritus) and the cumulative number of weeks free of angioedema was 8.81 with Rhapsido versus 6.68 with placebo.[1] HSS7 decreased by an average of 10.47 points with Rhapsido versus 6.00 with placebo and ISS7 by 8.95 points versus 5.72.[4] The recommended dose is 25 mg twice daily with or without food.[7][6] The drug inhibits the degranulation of mast cells and basophils, including the release of histamine and other pro-inflammatory mediators.[2] Studies have shown consistent results in controlling CSU symptoms at weeks 2 and 12.[1]