Novartis Korea wins nod for oral urticaria drug 'Rhapsido'

Underlying mechanism of inhibiting BTK…inhibits the inflammatory response at an early stage

Confirmed sustained effects and safety during long-term treatment

Rhapsido (remibrutinib)

Novartis Korea (CEO Yoo Byung-jae) announced on the 14th that 'Rhapsido (remibrutinib),' the first oral BTK inhibitor for the treatment of chronic urticaria, has received domestic approval in South Korea for the treatment of adult patients with Chronic Spontaneous Urticaria (CSU) whose symptoms are inadequately controlled by second-generation antihistamines.

Rhapsido is an oral inhibitor that targets Bruton's Tyrosine Kinase (BTK).

In the mast cell-activating process of CSU, BTK in mast cells triggers the release of inflammatory mediators, such as histamine, leading to symptoms including hives, angioedema, and itching.

By highly selectively inhibiting BTK, Rhapsido blocks the secretion of these inflammatory mediators at an early stage.

While conventional antihistamines treat the condition after histamine and other substances have already been released from mast cells, Rhapsido's strategy is to prevent their secretion from the start.

The approval was based on results from the global Phase 3 clinical trials, 'REMIX-1' and 'REMIX-2.' Both studies were multicenter, randomized, double-blind, placebo-controlled studies evaluating the efficacy and safety of Rhapsido in patients aged 18 and older with CSU inadequately controlled by H1-antihistamines.

Based on the study results, Rhapsido significantly improved the primary endpoint, which was the weekly Urticaria Activity Score (UAS7) at week 12 compared to the baseline. This result remained consistent through week 24.

By week 12, symptom improvement (UAS7 ≥ 10.5 reduction) was confirmed, with approximately 47–50% of patients achieving well-controlled status (UAS7 ≤ 6) and 28–31% experiencing complete symptom resolution (UAS7 = 0).

A 52-week long-term analysis showed that approximately 62% of patients maintained symptom control (UAS7 ≤ 6), while 45% maintained complete symptom resolution (UAS7 = 0).

The incidence of adverse events was similar between the Rhapsido group (64.9%) and the placebo group (64.7%), with most reactions being mild to moderate. This safety profile remained consistent throughout the 52-week treatment period.

Based on this clinical evidence, Rhapsido is recommended as an oral targeted therapy in the 2026 International Guideline for Urticaria for patients who are not adequately controlled despite increasing the dosage of second-generation antihistamines to 4 times the standard dose.

While antihistamines are widely used as first-line therapy, it is reported that symptoms persist in more than half of patients even with increased doses. Rhapsido addresses this significant unmet need as the first approved oral targeted therapy, offering rapid and significant symptom improvement along with the convenience of oral administration.

Professor Young-min Ye of the Department of Allergy and Clinical Immunology at Ajou University Hospital​ stated, "The introduction of a new mechanism of action targeting BTK is clinically significant because it offers hope for efficacy across a broader range of patients, regardless of the immunological variations in the pathogenesis of urticaria," and added, "It is particularly noteworthy that the treatment effect appears within one week and is sustained for up to 52 weeks." Furthermore, Ye added, "It is important to consider proactive treatment aimed at 'rapid and complete symptom management' by consulting with experts."

Park Joo-young, Executive Director of the Immunology Business Unit at Novartis Korea, stated, "CSU is a disease where symptoms recur unpredictably, placing a heavy burden on patients, especially those in socially and economically active age groups. The approval of Rhapsido marks a major turning point by providing a new treatment option for those who could not achieve sufficient symptom control with existing therapies." In conclusion, Park added, "Based on our expertise in the field of immunological diseases, Novartis Korea will continue to play a role in ensuring that CSU patients can plan their lives without the frustration of treatment failure."