Sanofi’s Wayrilz Gets U.S. FDA Approval As First BTK Inhibitor To Treat Adults With Immune Thrombocytopenia

The United States Food and Drug Administration (FDA) has granted approval for Wayrilz (rilzabrutinib) to be used in adults with persistent or chronic immune thrombocytopenia (ITP) who have not had a sufficient response to prior treatments. This marks the first approval of a Bruton’s tyrosine kinase (BTK) inhibitor for this condition in the US. The approval is based on results from the Phase 3 LUNA 3 study, which evaluated the safety and effectiveness of Wayrilz in comparison to placebo in 202 adults with ITP. 

The study demonstrated significant clinical benefits, including sustained increases in platelet counts and improvements in disease-related symptoms. At week 25, 23 percent of patients receiving Wayrilz achieved a durable platelet response, compared with none in the placebo group. The treatment also showed a faster time to first platelet response, with patients responding in an average of 36 days, while no response was reached in the placebo group. Additionally, the duration of platelet response was longer in the Wayrilz group, with a mean of seven weeks, compared with less than one week in the placebo arm.

Patients receiving Wayrilz also experienced a meaningful improvement in quality of life. Using the Immune Thrombocytopenia Patient Assessment Questionnaire, they reported an average 10.6-point improvement across nine health-related measures, compared with a 2.3-point increase in the placebo group. These results, while descriptive, highlight the broader benefit of the therapy beyond platelet counts.

Caroline Kruse, President and CEO at the Platelet Disorder Support Association, stated, 

“The burden of immune thrombocytopenia can be both physical and emotional with significant overlooked symptoms that can impact various aspects of daily living. 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."

Brian Foard, Executive Vice President, Head of Specialty Care at Sanofi, said in a statement, “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."

David Kuter, MD, Director of Clinical Hematology at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School, study author, mentioned, “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. 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 is an oral, reversible BTK inhibitor that works by modulating multiple immune pathways, aiming to address the underlying immune causes of ITP. The most common side effects observed in patients during clinical trials, reported in at least 10 percent of cases, included diarrhea, nausea, headache, abdominal pain, and COVID-19. This therapy has also been approved in the United Arab Emirates since June 2025 for adults with persistent or chronic ITP who did not respond or could not tolerate previous treatments. Regulatory reviews are ongoing in the European Union and China.

Wayrilz has received multiple regulatory designations recognizing its potential benefits for rare diseases. These include Fast Track and Orphan Drug Designation (ODD) from the FDA for ITP, as well as orphan status in Japan and the European Union. More recently, the FDA also granted ODD to Wayrilz for warm autoimmune hemolytic anemia, IgG4-related disease, and sickle cell disease. 

In addition, the drug has Fast Track status from the FDA and orphan designation from the European Medicines Agency for IgG4-related disease. To support patients, Sanofi will make Wayrilz available under its HemAssist program, which offers guidance on treatment access, insurance navigation, and financial assistance options, along with educational resources for patients and caregivers managing rare blood disorders.