Sanofi's rilzabrutinib earns EU orphan designation for IgG4-related disease treatment.

Sanofi's rilzabrutinib has received orphan designation in the EU for IgG4-related disease, a rare immune-mediated disease. The designation underscores Sanofi's commitment to advancing new medicines for rare diseases. Rilzabrutinib is a reversible covalent Bruton's tyrosine kinase inhibitor, and its efficacy in IgG4-RD was evaluated in a Phase 2 study presented at EULAR 2025 Congress.

Sanofi's investigational drug rilzabrutinib has received orphan designation in the EU for the treatment of IgG4-related disease (IgG4-RD), a rare immune-mediated condition. The designation, granted by the European Medicines Agency (EMA), underscores Sanofi's commitment to advancing new medicines for rare diseases.

Rilzabrutinib, a reversible covalent Bruton's tyrosine kinase (BTK) inhibitor, demonstrated efficacy in a Phase 2 study (clinical study identifier: NCT04520451) presented at the European Alliance of Associations for Rheumatology (EULAR) 2025 Congress. The study showed that treatment with rilzabrutinib for 52 weeks led to a reduction in disease flare-ups, other disease markers, and glucocorticoid sparing in IgG4-RD patients. The safety profile of rilzabrutinib was consistent with previous studies, with no new safety signals observed.

The orphan designation for IgG4-RD follows similar designations for immune thrombocytopenia (ITP) in the US, the EU, and Japan, as well as 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 for ITP and IgG4-RD. The drug is currently under regulatory review in the US, the EU, and China for its potential use in ITP, with a target action date for the US FDA regulatory decision of August 29, 2025.

Rilzabrutinib is an investigational agent, and its safety and efficacy have not been evaluated by any regulatory authority. The drug is designed to restore immune balance via multi-immune modulation by selectively inhibiting BTK, which plays a critical role in multiple immune-mediated disease processes and inflammatory pathways.

References:
[1] https://finance.yahoo.com/news/press-release-sanofi-rilzabrutinib-earns-050000870.html
[2] https://www.globenewswire.com/news-release/2025/08/14/3133146/0/en/Press-Release-Sanofi-s-rilzabrutinib-earns-orphan-designation-in-the-EU-for-IgG4-related-disease.html