The US Food and Drug Administration (FDA) has approved Sanofi’s Wayrilz (rilzabrutinib) as the first Bruton’s tyrosine kinase (BTK) inhibitor for adults with persistent or chronic immune thrombocytopenia (ITP) who have not responded to previous treatments. The approval is based on results from the LUNA 3 phase 3 study, which demonstrated that Wayrilz led to rapid and sustained increases in platelet counts and improvements in other ITP symptoms.
“The burden of immune thrombocytopenia can be both physical and emotional with significant overlooked symptoms that can impact various aspects of daily living,” said Caroline Kruse, President and CEO at the Platelet Disorder Support Association. “We are pleased to have a new treatment option that can help ease the ongoing strain of managing the disease for patients and their families.”
Wayrilz is an oral, reversible BTK inhibitor designed to target multiple pathways in the immune system. According to Brian Foard, Executive Vice President, Head of Specialty Care at Sanofi, “With its differentiated mechanism of action, Wayrilz has the potential to become a treatment of choice for immune thrombocytopenia patients who have not responded to a prior therapy. Its multi-immune modulation approach shows promise in addressing the key drivers of immune thrombocytopenia, which aligns with Sanofi’s commitment to adapting and evolving therapeutic solutions to help tackle ongoing unmet patient needs. This approval underscores Sanofi’s expertise and ambitions at the junction of rare and immunological disease.”
In the LUNA 3 study presented at the American Society of Hematology Annual Meeting, adults treated with Wayrilz showed a statistically significant durable platelet response at week 25 compared to placebo (23% vs. 0%), faster time to first platelet response (36 days vs. not reached), and longer duration of platelet response (7 weeks vs. 0.7 weeks). Patients also reported greater improvements in health-related quality of life measures compared to those receiving placebo.
Common side effects included diarrhea, nausea, headache, abdominal pain, and COVID-19.
“Traditionally, immune thrombocytopenia management has focused on restoring platelet counts and reducing bleeding risk, which for some patients may result in suboptimal responses, persistent symptoms, or unacceptable treatment complications,” said David Kuter, MD, Director of Clinical Hematology at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School. “Through multi-immune modulation, Wayrilz can offer a new option for patients, including those who fail steroids or do not respond to existing treatment.”
Wayrilz was previously approved in June 2025 in the United Arab Emirates for similar use in adults with ITP who had insufficient response or intolerance to prior treatments. Regulatory review is ongoing in both the European Union and China.
The FDA granted Fast Track and Orphan Drug Designations for Wayrilz in ITP; similar orphan designations were received in Japan and Europe. The FDA also recently awarded Orphan Drug Designation for three additional rare diseases: warm autoimmune hemolytic anemia (wAIHA), IgG4-related disease (IgG4-RD), and sickle cell disease (SCD). The drug also holds Fast Track Designation from the FDA and orphan designation from the European Medicines Agency for IgG4-RD.
Patients prescribed Wayrilz will have access to Sanofi’s HemAssist program offering support services such as insurance navigation, financial assistance eligibility determination, educational resources, and more information via https://www.sanofihemassist.com or by calling 1-833-723-5463.
The LUNA 3 trial involved adult participants with persistent or chronic ITP receiving either oral Wayrilz or placebo over a double-blind period up to 24 weeks followed by open-label extension. The primary endpoint was achieving durable platelet response without rescue therapy during specified measurements near study end; secondary endpoints included time-to-response metrics as well as fatigue and bleeding scores.
ITP is characterized by low platelet counts due to complex immune dysregulation leading to bleeding risks—including potentially life-threatening episodes—and reduced quality of life due to fatigue or cognitive impairment.
Sanofi describes itself as an R&D-driven biopharmaceutical company applying advanced research into medicines targeting immunological diseases among others.
