France-based pharmaceutical company Servier has announced the acquisition of Day One Biopharmaceuticals for $2.5 billion. Day One, which began operations in 2020 with a $60 million Series A funding round, focuses on developing cancer therapies for both adults and children, with an emphasis on pediatric oncology.
The acquisition is part of Servier’s strategy to address significant unmet needs in oncology by 2030. Through this deal, Servier will add Day One’s portfolio, which includes Ojemda—a drug approved by the FDA in 2024 for treating pediatric glioma. Ojemda generated $155.4 million in sales during 2025, according to Day One’s February earnings call.
Servier offered $21.50 per share in cash for Day One’s stock, giving the transaction a total equity value of $2.5 billion. Following the announcement, shares of Day One rose by 65% to reach $21.14 on Friday morning.
Founded in the 1950s, Servier specializes in oncology, neurology, and cardiometabolic diseases. Its cancer treatments include chemotherapy drugs and targeted therapies for blood cancers and solid tumors. In addition to acquiring Ojemda through this deal, Servier also markets Voranigo—another FDA-approved treatment for glioma targeting patients with IDH1 or IDH2 mutations.
Day One expanded its pipeline further after becoming a commercial entity in 2024 by acquiring Mersana Therapeutics for up to $285 million later that year. This acquisition brought antibody-drug conjugates (ADCs) focused on rare adult cancers into its portfolio; among them is emiltatug ledadotin (Emi-Le), which is expected to have updated Phase 1 data released this year regarding adenoid cystic carcinoma.
Day One CEO Jeremy Bender commented: “Servier’s successful track record in rare cancers and its commitment to advancing targeted therapies makes it the ideal home for our portfolio as part of Day One’s mission to bring medicines to patients of all ages with life threatening diseases.”
Ojemda was one of several new drugs that received first-time approvals from the FDA in 2024 alongside products from Madrigal Pharmaceuticals and X4 Pharmaceuticals.
