• Data from the positive Phase 2 study evaluating rilzabrutinib for the treatment of IgG4-related disease presented at EULAR 2025
• Additional orphan designation underscores Sanofi commitment to advancing new medicines in immune-mediated rare diseases

The European Medicines Agency has granted orphan designation to rilzabrutinib, a reversible covalent Bruton’s tyrosine kinase (BTK) inhibitor, for IgG4-related disease (IgG4-RD). EMA grants orphan designation to investigational therapies addressing rare, life-threatening or debilitating medical diseases or conditions that affect no more than 5 in 10,000 persons in the EU.

Rilzabrutinib for the treatment of IgG4-related disease was evaluated in a phase 2 study (clinical study identifier: NCT04520451) and results were presented at the European Alliance of Associations for Rheumatology (EULAR) 2025 Congress. In IgG4-RD patients, treatment with rilzabrutinib for 52 weeks led to reduction in disease flare, other disease markers, and glucocorticoid sparing. The safety profile of rilzabrutinib in the study was consistent with previous studies, with no new safety signals observed.

In addition to IgG4-related disease, rilzabrutinib has received orphan designations for immune thrombocytopenia (ITP) in the US, the EU, and Japan; and for warm autoimmune hemolytic anemia,  IgG4-RD and sickle cell disease in the US. Rilzabrutinib has also been granted fast track designation in the US in ITP and IgG4-RD.

Rilzabrutinib is currently under regulatory review in the US, the EU, and China for its potential use in ITP. The target action date for the US FDA regulatory decision for ITP, which was granted fast track designation, is August 29, 2025.

Rilzabrutinib is an investigational agent, and its safety and efficacy have not been evaluated by any regulatory authority.