Sanofi has secured Blueprint Medicines for $9.1 billion upfront, gaining access to the oral tyrosine kinase inhibitor Ayvakit (avapritinib) approved for systemic mastocytosis and a robust pipeline including next-generation KIT inhibitors. Blueprint’s kinase inhibitors target the KIT D816V mutation prevalent in over 95% of advanced systemic mastocytosis cases. The acquisition enhances Sanofi’s immunology portfolio and pipeline diversity, particularly in rare immunological disorders. Blueprint Medicines, backed by venture investment and public markets since 2015, had reached nearly $500 million annual revenue from Ayvakit sales in 2024.