The FDA granted approval to Sanofi's BTK inhibitor rilzabrutinib, acquired through its $3.7 billion Principia Biopharma buyout, for the treatment of immune thrombocytopenia. This marks a significant advancement in Sanofi's immunology portfolio, providing a novel oral therapeutic option for a rare but serious hematologic condition. The approval reinforces Sanofi’s strategy of leveraging targeted kinase inhibitors in autoimmune and inflammatory diseases.