Phase 3 Data Confirms Long-Term Efficacy, Sustained Safety of Oral Remibrutinib for CSU

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Novartis today announced late-breaking data supporting and confirming the long-term efficacy and sustained safety of oral Bruton’s tyrosine kinase inhibitor (BTK) remibrutinib in chronic spontaneous urticaria (CSU).¹ The data were shared at the 2024 European Academy of Allergy and Clinical Immunology Congress in Valencia, Spain.

The new data stems from the phase 3 REMIX-1 and REMIX-2 studies,² wherein results indicated significant symptom improvement among patients with CSU with prior second-generation H1-antihistamine use. Symptom improvement was both rapid and sustained through week 52 of the studies.

The phase III trials had previously reported significant improvements in various symptom scores at week 12, and these benefits were confirmed at week 24. Key metrics included:

• Weekly Urticaria Activity Score (UAS7): Significant reductions in UAS7 were noted in patients treated with remibrutinib.
• Weekly Itch Severity Score (ISS7): Patients on remibrutinib reported marked decreases in itch severity.
• Weekly Hive Severity Score (HSS7): Similar to the UAS7 and ISS7, patients experienced considerable improvements.

At the 24-week mark, those initially on placebo were transitioned to remibrutinib. These patients showed significant symptom improvement as early as the first week after switching, with sustained benefits observed throughout the remaining study period.

Furthermore, by week 52, nearly half of the patients achieved complete relief from itch and hives, reflected by a UAS7 score of 0.

Remibrutinib was well-tolerated with a consistent safety record over the 52 weeks. The incidence of adverse events (AEs), including serious AEs and treatment discontinuations due to AEs, was comparable between the remibrutinib and placebo groups during the initial 24-week placebo-controlled phase.

Liver function tests were balanced across both treatment groups, with any elevations in liver transaminases being asymptomatic, transient, and reversible. None of the serious AEs reported were deemed related to the study medication.

“A large majority of people with CSU are living with uncontrolled and debilitating symptoms, often trying to manage the condition by cycling through antihistamines at higher doses with no lasting respite, impacting heavily on their day-to-day lives,” said Martin Metz, professor of dermatology atCharité-Universitätsmediz in Berlin, Germany, in a news release.¹ “Remibrutinib has become an important investigational treatment for CSU as it blocks the BTK cascade and inhibits the release of histamine. These data show that remibrutinib has the potential to offer patients and physicians a well-tolerated oral treatment that provides early and lasting efficacy.”

Novartis plans to submit remibrutinib for CSU to global health authority for approvals in the second half of 2024.¹

“Living with CSU can be very distressing due to its unpredictable nature and never knowing when a flare-up may happen. Symptoms can occur on the face, throat, hands, and feet, and people may experience burning and pain on their skin,” said Tonya Winders, president and CEO of the Global Allergy and Airways Patient Platform.¹ "Unfortunately, many people continue to cope with uncontrolled symptoms. We welcome further research advancing our knowledge about chronic spontaneous urticaria.”

References

1. Novartis phase III data confirm sustained efficacy and long-term safety of oral remibrutinib in chronic spontaneous urticaria. News release. Novartis. May 31, 2024. Accessed May 30, 2024.
2. Saini S, Giménez-Arnau A, Hide M, et al. Fast symptom improvement and favorable safety profile with remibrutinib in chronic spontaneous urticaria: REMIX-1/-2 studies. Ann Allergy Asthma Immunol. 2023;131(6):1234-1245. doi:10.1016/j.anai.2023.04.123