French pharmaceutical company Servier announced on Friday that it will acquire U.S.-based Day One Biopharmaceuticals for approximately $2.5 billion to expand its brain cancer treatment portfolio.

Servier offered $21.50 per share in cash, representing a 68% premium over Day One Biopharma's previous closing price. Following the announcement, Day One's stock surged 65% in early trading.

The acquisition will provide Servier with Day One's key drug, Ojemda. It is the only monotherapy approved by the U.S. FDA for treating pediatric low-grade glioma, the most common type of brain tumor in children.

Servier already markets Vorasidenib for adult glioma, and this acquisition will further strengthen its presence in the field. The company is actively building a pipeline focused on rare cancers, with a goal of reaching €10 billion (approximately $11.58 billion) in annual revenue by 2030.

Ojemda was approved in 2024 for patients whose tumors progressed after prior treatment. Clinical trials for first-line use are currently underway, with results expected in the second half of 2027.

Wedbush Securities analyst Robert Driscoll described Day One as a "highly attractive acquisition target," largely due to Ojemda's successful launch and significant sales potential if approved for first-line treatment around 2028.

The drug generated $155.4 million in sales in 2025, with projections indicating growth to $225–250 million in 2026.

Ojemda's main competitor is Novartis's combination therapy Tafinlar + Mekinist, which requires daily dosing, whereas Ojemda is administered just once per week.

Both companies stated that the transaction is expected to close in the second quarter of 2026, with Servier funding the deal through existing cash and investments.