Rilzabrutinib Phase 2: Rapid Relief for Chronic Urticaria Itch in Adults

Rilzabrutinib Shown to Alleviate Chronic Spontaneous Urticaria in Phase 2 Study
A recent Phase 2 clinical trial, RILECSU, has indicated that rilzabrutinib, an orally administered BTK inhibitor, could be a promising treatment for adults suffering from chronic spontaneous urticaria (CSU). The study, which was highlighted at the 2024 American Academy of Allergy, Asthma, and Immunology (AAAAI) Annual Meeting, revealed that the drug led to a significant reduction in itch severity and disease activity from the first week of treatment.
The positive outcomes have prompted the initiation of Phase 3 trials for CSU and prurigo nodularis, set to commence in 2024. Additionally, pivotal Phase 3 results for immune thrombocytopenia and Phase 2 results for asthma, IgG4-related disease, and warm autoimmune hemolytic anemia are anticipated within the same year. Rilzabrutinib is part of Sanofi's leading immunology pipeline, which includes 12 potential blockbuster drugs.
Professor Marcus Maurer, a dermatology and allergy expert, emphasized the severe impact of CSU on patients' daily lives and the need for alternative treatments for those not adequately controlled by antihistamines. Naimish Patel, Head of Global Development for Immunology and Inflammation at Sanofi, highlighted the drug's potential to reduce the physical and psychosocial burden on patients and the plans to advance rilzabrutinib into Phase 3 development.
The Phase 2 study involved a dose-ranging approach, with rilzabrutinib administered at varying frequencies. The highest dosage, taken three times daily, demonstrated significant improvements in itch severity, urticaria activity, and hives severity scores. The drug was well-tolerated, with the most common side effects being diarrhea, nausea, headache, and abdominal pain.
CSU is an inflammatory condition often resistant to H1 antihistamines and biologics, leaving many patients with limited treatment options. Rilzabrutinib, utilizing Sanofi's TAILORED COVALENCY® technology, targets BTK in B cells and mast cells, which are pivotal in immune-mediated diseases, potentially offering a new treatment option.
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About the Study and Drug:
The RILECSU study is a 52-week Phase 2 clinical trial assessing the efficacy and safety of rilzabrutinib in adults with moderate-to-severe CSU who do not respond well to H1 antihistamines.
The primary endpoint was the change in weekly itch severity score at 12 weeks, with secondary endpoints including changes in urticaria and hives severity scores.
Rilzabrutinib is an innovative BTK inhibitor that could potentially become a first- or best-in-class treatment for various immune-mediated diseases.