French pharmaceutical giant Sanofi has announced plans to acquire U.S.-based Blueprint Medicines Corporation , a biopharma firm focused on treating systemic mastocytosis—a rare immune-related disease. According to a joint statement released Monday, Sanofi will pay $129.00 per share in cash, valuing the deal at roughly $9.1 billion.
The acquisition “represents a strategic step forward in our rare and immunology portfolios. It enhances our pipeline and accelerates our transformation into the world’s leading immunology company,” said Sanofi CEO Paul Hudson.
The acquisition will strengthen Sanofi’s portfolio by adding Ayvakit/Ayvakyt (avapritinib), a rare disease treatment approved in both the U.S. and EU, along with a robust pipeline of early- and late-stage immunology candidates.
According to the companies, Blueprint’s strong relationships with allergists, dermatologists, and immunologists will further support Sanofi’s expanding presence in the immunology space. Ayvakit/Ayvakyt remains the only approved therapy for both advanced and indolent systemic mastocytosis—a rare immune disorder marked by abnormal mast cell buildup in the bone marrow, skin, gastrointestinal tract, and other organs.
The acquisition will also include elenestinib, a next-generation therapy for systemic mastocytosis, and BLU-808, an oral wild-type KIT inhibitor with strong potential to address a wide range of immunological diseases. In addition to the $129.00 per share cash payment at closing, Blueprint shareholders will receive a non-tradeable contingent value right (CVR), entitling them to two possible milestone payments of $2 and $4 per CVR, based on future development and regulatory progress for BLU-808.
With these CVR payments factored in, the total equity value of the transaction could reach approximately $9.5 billion on a fully diluted basis. Sanofi CEO Paul Hudson noted that the deal aligns with the company’s strategy of acquiring promising early-stage medicines and confirmed that Sanofi still maintains substantial capacity for future acquisitions.
