Rilzabrutinib Gains Regulatory Nods in the U.S. and Japan
The U.S. FDA has granted breakthrough therapy designation and Japan’s MHLW has designated orphan drug status to Sanofi’s BTK inhibitor, rilzabrutinib (Wayrilz), as a treatment for wAIHA.
In a Feb. 9, 2026 press release, Sanofi revealed that its oral reversible covalent BTK inhibitor, rilzabrutinib (Wayrilz), has secured breakthrough therapy designation from the U.S. FDA as well as orphan drug status from Japan’s Ministry of Health, Labour, and Welfare (MHLW). These regulatory affirmations further support the company actions towards strengthening its rare disease portfolio (1).
The rare potentially life-threatening autoimmune disorder, warm autoimmune hemolytic anemia (wAIHA), affects 60–70% of AIHA cases, where autoantibodies react optimally at body temperature (37 °C) to cause immune-mediated red blood cell destruction (hemolysis). Patients often suffer debilitating symptoms including chronic anemia, fatigue, dizziness, palpitations, shortness of breath and complications, such as thromboembolism or serious organ damage (2,3). In the U.S. and EU, AIHA impacts an estimated 4 to 24 people per 100,000, while in Japan it affects 3 to 10 per million.
Rilzabrutinib selectively and reversibly inhibits BTK — an enzyme expressed in B cells, macrophages, and other innate immune cells that plays a critical role in various immune-mediated disease processes and inflammatory pathways. In wAIHA, this modulation targets dysregulated pathways driving B-cell autoantibody production and effector functions that exacerbate hemolysis, while avoiding the irreversible covalent binding of first-generation BTK inhibitors (1).
The FDA breakthrough therapy designation and Japan’s MHLW orphan status for rilzabrutinib stem from promising data in the Phase IIb LUMINA 2 trial (NCT05002777), which demonstrated clinically meaningful improvements in hemoglobin levels, hemolysis markers and overall efficacy in heavily pretreated wAIHA patients. Sanofi is now enrolling in the pivotal Phase III LUMINA 3 study (NCT07086976), comparing rilzabrutinib against placebo to confirm these benefits.
“These recognitions highlight the critical unmet need that persists for people living with wAIHA,” said Karin Knobe, Global Head of Development, Rare Diseases, Sanofi, in the company press release (1). “Furthermore, receiving such designations reinforces our commitment to advancing innovative medicines for rare diseases that currently have limited or no approved treatment options.”
For Sanofi, the designations accelerate the development and review of rilzabrutinib in both the U.S. and Japan. Rilzabrutinib, already approved as Wayrilz for immune thrombocytopenia (ITP) in the U.S., EU, and UAE — and under review in Japan — could span a spectrum of rare disease indications, and further strengthen Sanofi’s R&D focus on artificial intelligence-powered biopharma innovations for immune-mediated conditions.
References
Sanofi. Sanofi’s Rilzabrutinib Designated Breakthrough Therapy in the US and Orphan Drug in Japan for the Treatment of Warm Autoimmune Hemolytic Anemia. Press Release, Feb. 9, 2026.
National Organization for Rare Diseases. Warm Autoimmune Hemolytic Anemia. Rarediseases.org, accessed Feb. 11, 2026.
Rare Voices Australia. Warm Autoimmune Haemolytic Anaemia (wAIHA). Rareportal.org.au, accessed Feb. 11, 2026.