The UK MHRA has authorised Rhapsido (remibrutinib), the first oral BTK inhibitor for adults with chronic spontaneous urticaria uncontrolled by H1 antihistamines.
Written By: Kalyani Boharapi,
M.Pharm (Reg. Affairs)
Reviewed By: Pharmacally Editorial Team
The UK Medicines and Healthcare products Regulatory Agency has granted marketing authorisation to Rhapsido® (remibrutinib) for the treatment of adult patients with chronic spontaneous urticaria (CSU) whose disease remains inadequately controlled despite treatment with H1 antihistamines. The approval makes remibrutinib the first oral Bruton’s tyrosine kinase (BTK) inhibitor authorised in the UK for this patient population.
MHRA Approval Supported by Phase III REMIX Trials
The MHRA authorisation is supported by findings from the pivotal REMIX-1 (NCT05030311) and REMIX-2 (NCT05032157) Phase III clinical trials, which enrolled 925 adults with chronic spontaneous urticaria who remained symptomatic despite treatment with second-generation H1 antihistamines.
Both randomised, placebo-controlled studies met their primary endpoint by demonstrating statistically significant improvements in the Weekly Urticaria Activity Score (UAS7) at Week 12 compared with placebo.
In REMIX-1, patients receiving remibrutinib achieved a mean reduction in UAS7 of 20.0 points, compared with 13.8 points in the placebo group. In REMIX-2, the corresponding reductions were 19.4 points and 11.7 points, respectively.
The studies also met all key secondary endpoints, including significant improvements in itch severity and hive severity, supporting the overall efficacy of remibrutinib in patients with inadequately controlled CSU.
Safety Profile
The safety profile of remibrutinib was consistent with previous clinical studies and remained stable throughout the 52-week study period.
The most frequently reported adverse reactions were upper respiratory tract infections (14.7%), including nasopharyngitis (6.6%) and influenza (2.5%). Overall, the treatment demonstrated an acceptable safety profile consistent with previous clinical experience.
About Chronic Spontaneous Urticaria
Chronic spontaneous urticaria is a chronic inflammatory skin disorder characterised by recurrent hives (wheals), intense itching, and, in some patients, angioedema occurring without an identifiable external trigger for six weeks or longer.
The condition can substantially impair quality of life by disrupting sleep, daily activities, work productivity, and mental well-being. CSU affects adults of all ages but is most commonly diagnosed between 20 and 40 years of age, with women affected nearly twice as often as men. Approximately half of patients continue to experience symptoms despite treatment with H1 antihistamines.
About Remibrutinib
Remibrutinib is a highly selective, orally administered Bruton’s tyrosine kinase (BTK) inhibitor designed to suppress mast cell and basophil activation by inhibiting BTK-dependent signalling pathways involved in the release of histamine and other inflammatory mediators.
By targeting key immune mechanisms underlying chronic spontaneous urticaria, remibrutinib offers a novel oral treatment option for patients whose disease remains inadequately controlled with standard antihistamine therapy.
Expanding Treatment Options for CSU
The MHRA approval of Rhapsido introduces a new oral treatment option for adults with chronic spontaneous urticaria who continue to experience symptoms despite H1 antihistamine treatment. Supported by positive Phase III REMIX trial results demonstrating clinically meaningful improvements in disease activity together with a favourable safety profile, the authorisation expands the available therapeutic options for patients living with this chronic and often debilitating condition.
Reference
MHRA approves remibrutinib for adults with chronic spontaneous urticaria – GOV.UK
About the Writer
Kalyani Boharapi (LinkedIn) is a pharmacy professional and healthcare writer currently pursuing an M.Pharm in Regulatory Affairs at Dr. D. Y. Patil College of Pharmacy, with interests in pharmaceutical regulations, drug development, and healthcare innovation. She has academic exposure to dossier preparation, scientific writing, and regulatory documentation. Kalyani has also completed certification courses in Generative AI, AI in Pharma, and Bioinformatics, and actively participates in pharmaceutical conferences to stay updated with emerging trends and advancements in the healthcare and pharmaceutical industry.