Sanofi announced that its oral drug rilzabrutinib, marketed as Wayrilz where approved, has received breakthrough therapy designation from the US Food and Drug Administration (FDA) for the treatment of warm autoimmune hemolytic anemia (wAIHA). The Japanese Ministry of Health, Labour and Welfare has also granted orphan drug status to rilzabrutinib for the same rare condition.
The FDA’s decision is based on data from the ongoing LUMINA 2 phase 2b clinical trial (NCT05002777), which evaluates the safety and efficacy of rilzabrutinib in patients with wAIHA. A separate phase 3 study, LUMINA 3 (NCT07086976), is currently comparing rilzabrutinib to placebo in this patient population. Currently, there are no approved therapies that specifically target the underlying cause of wAIHA, a disorder characterized by immune-mediated destruction of red blood cells leading to symptoms such as anemia and fatigue.
According to Sanofi, an FDA breakthrough therapy designation aims to speed up development and review processes for drugs treating serious or life-threatening diseases when early evidence suggests substantial improvement over existing treatments. Orphan designation in Japan is given to medicines addressing rare diseases with significant unmet medical needs.
“These recognitions highlight the critical unmet need that persists for people living with wAIHA,” said Karin Knobe, Global Head of Development, Rare Diseases at Sanofi. “Furthermore, receiving such designations reinforces our commitment to advancing innovative medicines for rare diseases that currently have limited or no approved treatment options.”
Rilzabrutinib is already approved under the brand name Wayrilz for adults with immune thrombocytopenia (ITP) in the US, European Union, and United Arab Emirates. It is currently under regulatory review for ITP in Japan. Other uses remain investigational.
Previously, rilzabrutinib received orphan drug status from the FDA not only for autoimmune hemolytic anemia but also for IgG4-related disease (IgG4-RD) and sickle cell disease (SCD). The FDA has also granted fast track designation to rilzabrutinib for ITP and IgG4-RD; it holds EU orphan status in ITP, autoimmune hemolytic anemia, and IgG4-RD.
Warm autoimmune hemolytic anemia affects between four and 24 people per 100,000 in the US and EU; prevalence is lower in Japan at three to ten cases per million. Patients may experience severe fatigue and complications such as thromboembolism due to premature red blood cell destruction caused by autoantibodies.
Rilzabrutinib works by selectively inhibiting Bruton’s tyrosine kinase (BTK), a protein involved in several immune system pathways implicated in rare inflammatory disorders. In addition to studies on ITP and wAIHA, Sanofi is investigating rilzabrutinib’s potential use in other conditions including IgG4-RD and SCD.
Sanofi describes itself as an R&D-driven biopharmaceutical company focused on developing medicines targeting complex immune system dysfunctions across various rare diseases worldwide.
