PARIS, June 23, 2026
Sanofi has secured an important regulatory milestone after Japan’s Ministry of Health, Labour and Welfare granted marketing and manufacturing authorization for Wayrilz® (rilzabrutinib) to treat persistent or chronic immune thrombocytopenia (ITP) in adults who have not responded adequately to existing therapies or cannot tolerate current treatment options. The approval expands the global availability of Wayrilz, a novel oral reversible Bruton’s tyrosine kinase (BTK) inhibitor, and reinforces Sanofi’s growing leadership in rare immune-mediated diseases. Unlike conventional therapies that primarily manage symptoms, Wayrilz works through multi-immune modulation, targeting several immune pathways involved in the underlying disease process. The approval is supported by positive results from the Phase 3 LUNA 3 clinical trial, where the investigational therapy demonstrated rapid, durable platelet responses together with improvements in patient symptoms and quality of life. The latest authorization represents another significant advance for patients living with immune thrombocytopenia, a rare autoimmune disease associated with dangerously low platelet counts, bleeding complications, and reduced quality of life.
Phase 3 LUNA 3 Trial Demonstrates Durable Clinical Benefit
The approval is based on the global LUNA 3 Phase 3 study, which enrolled 202 adults with persistent or chronic immune thrombocytopenia. The trial successfully met both its primary and secondary endpoints, confirming the clinical effectiveness of Wayrilz® compared with placebo. Patients receiving the therapy achieved statistically significant durable platelet responses at Week 25, experienced a faster time to first platelet response, and maintained platelet improvements for substantially longer periods than those receiving placebo. In addition to improving platelet counts, patients treated with Wayrilz also reported meaningful improvements in overall quality of life, including reductions in fatigue and disease-related symptoms measured using validated patient assessment tools. The treatment maintained a favorable safety profile, with the most commonly reported adverse reactions including diarrhea, nausea, headache, abdominal pain, and COVID-19 infections, consistent with previous clinical experience.
Novel BTK Inhibitor Targets the Root Cause of ITP
Wayrilz® (rilzabrutinib) is a first-in-class oral reversible covalent BTK inhibitor developed to restore immune balance through multi-immune modulation rather than simply increasing platelet production. By selectively inhibiting Bruton’s tyrosine kinase (BTK) across multiple immune cell populations, the therapy addresses the complex immune dysregulation responsible for immune thrombocytopenia. ITP is characterized by immune-mediated destruction of platelets, increasing the risk of bruising, severe bleeding, fatigue, and thromboembolic complications. Beyond treating platelet deficiency, Wayrilz has demonstrated the potential to improve broader disease manifestations that significantly impact daily living. The medicine is also being investigated in several additional rare immune-mediated diseases, including IgG4-related disease (IgG4-RD), warm autoimmune hemolytic anemia (wAIHA), and sickle cell disease, highlighting its broader therapeutic potential.
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Global Expansion Reinforces Sanofi’s Rare Disease Strategy
The latest Japanese approval further strengthens Sanofi’s expanding rare disease portfolio, with Wayrilz® now approved in the United States, European Union, United Kingdom, United Arab Emirates, and Japan for immune thrombocytopenia. The approval reflects Sanofi’s continued investment in innovative immunology therapies designed to address diseases with substantial unmet medical needs. In Japan, the therapy has also received Orphan Drug designation for ITP, IgG4-related disease, and warm autoimmune hemolytic anemia, supporting future regulatory development in additional indications.
As global research continues to explore the role of BTK inhibition across autoimmune and inflammatory diseases, Wayrilz represents an important scientific advancement capable of transforming treatment for patients living with rare hematological disorders. The approval also reinforces Sanofi’s long-term strategy of combining immune science, precision medicine, and innovative therapeutic mechanisms to deliver meaningful clinical improvements for patients facing complex immune-mediated diseases worldwide.
Source: Sanofi press release
