Mersana Therapeutics (MRSN) Soars on Up to $285 Million Day One Biopharmaceuticals Buyout: All the Key News on November 13, 2025
Day One Biopharmaceuticals will acquire Mersana Therapeutics in a deal valued at up to $285 million, offering $25 per share in cash plus contingent value rights up to $30.25 per share. Mersana’s board and major holders support the agreement. MRSN shares jumped as much as 200% pre-market. Halper Sadeh LLC launched a shareholder fairness investigation.
