Pharma BD Deal Intelligence
Sanofi acquired Principia Biopharma in an all-cash tender offer at $100/share (~$3.68 billion), announced August 17, 2020 and completed September 28, 2020, to build out its autoimmune and neurology pipeline around Principia's oral BTK-inhibitor platform. The two lead assets diverged post-close: rilzabrutinib, a reversible covalent BTK inhibitor, won FDA approval as WAYRILZ on August 29, 2025 for persistent or chronic immune thrombocytopenia (ITP) -- the first BTK inhibitor approved for ITP, with subsequent EU and UAE approvals. Tolebrutinib, the brain-penetrant BTK inhibitor positioned as the deal's headline multiple sclerosis asset, received an FDA Complete Response Letter on December 24, 2025 for non-relapsing secondary progressive MS (nrSPMS); Sanofi stated it would work with the FDA on a path forward.