Japan has approved Sanofi’s Wayrilz (rilzabrutinib) for chronic immune thrombocytopenia (ITP), backed by Phase 3 data showing durable platelet responses and improved quality of life.
Written By: Nikita Jha, BPharm
Reviewed By: Pharmacally Editorial Team
The Japanese Ministry of Health, Labour and Welfare has approved Sanofi’s Wayrilz (rilzabrutinib) for the treatment of persistent or chronic immune thrombocytopenia (ITP) in patients who experience insufficient response or poor tolerability with existing therapies. The authorization marks another major regulatory milestone for the oral Bruton’s tyrosine kinase (BTK) inhibitor, which is already approved in the United States, European Union, United Kingdom, and United Arab Emirates.
The approval was supported by positive results from the Phase 3 LUNA 3 trial (NCT04562766), which demonstrated that rilzabrutinib significantly improved platelet responses and other disease-related outcomes compared with placebo.
A Novel Approach to Immune Thrombocytopenia
ITP is a rare autoimmune disorder characterized by low platelet counts, typically below 100,000/μL, resulting from complex immune dysregulation. Patients face an increased risk of bruising, bleeding, and potentially life-threatening complications such as intracranial hemorrhage. Many also report persistent fatigue, cognitive difficulties, and reduced quality of life.
Wayrilz is a reversible covalent BTK inhibitor that works through multi-immune modulation. By targeting BTK signaling in B cells, macrophages, and other innate immune cells, the therapy addresses several immune pathways involved in platelet destruction and impaired platelet production. This mechanism differentiates rilzabrutinib from treatments that primarily focus on symptom control.
Phase 3 LUNA 3 Trial Met Primary and Secondary Endpoints
The randomized, placebo-controlled LUNA 3 study enrolled 202 adults with persistent or chronic ITP. Patients who achieved a platelet response after 12 weeks could continue treatment through the full 24-week double-blind period.
Rilzabrutinib met both primary and secondary endpoints. At Week 25, 23% of treated patients achieved a statistically significant durable platelet response compared with no patients in the placebo group (p<0.0001).
The therapy also accelerated platelet recovery, with a median time to first platelet response of 36 days, while the placebo group did not reach a median response. Patients receiving rilzabrutinib maintained platelet responses longer, with a least-square mean duration of seven weeks compared with 0.7 weeks for placebo.
Quality-of-life outcomes also favored rilzabrutinib. Patients reported a 10.6-point improvement in overall quality-of-life scores on the Immune Thrombocytopenia Patient Assessment Questionnaire versus a 2.3-point increase with placebo. Although the analysis was descriptive and not powered for statistical significance, the findings suggest broader patient benefits beyond platelet count improvement.
The most common adverse events reported with Wayrilz were diarrhea, nausea, headache, abdominal pain, and COVID-19 infection.
Expanding Rare Disease Development
Clinical investigators highlighted the importance of achieving near-normal platelet counts while reducing concerns about bleeding and fatigue. Sanofi noted that many patients continue to experience symptoms despite available therapies, creating a need for additional treatment options with novel mechanisms.
Beyond ITP, rilzabrutinib remains under investigation in several rare immune-mediated diseases, including IgG4-related disease, warm autoimmune hemolytic anemia, and sickle cell disease. Japan has granted orphan drug designation for rilzabrutinib in ITP, IgG4-related disease, and warm autoimmune hemolytic anemia, supporting continued development across these rare conditions.
With approvals now spanning the United States, European Union, United Kingdom, United Arab Emirates, and Japan, Sanofi is advancing a coordinated strategy to broaden patient access to Wayrilz worldwide
What This Means for Patients
For people living with chronic immune thrombocytopenia (ITP), Wayrilz provides a new option when existing therapies fail to deliver adequate benefit or cause intolerable side effects. In clinical studies, the oral therapy helped more patients achieve and sustain healthier platelet counts, reducing bleeding risk and easing fatigue. The approval offers patients and physicians an additional tool to better manage this challenging autoimmune disease and improve quality of life.
Reference
Press Release: Sanofi’s Wayrilz approved in Japan to treat immune thrombocytopenia
About the Writer
Nikita Jha, BPharm (LinkedIn) a pharmacy graduate specializing in medical writing, with a strong ability to interpret complex medical and regulatory information and translate it into clear, accurate, and evidence-based healthcare content. Known for her attention to detail and precision, she focuses on delivering high-quality scientific communication that supports drug safety and informed decision-making.