Day One Biopharma acquires Mersana Therapeutics

Day One Biopharma agreed to acquire Mersana Therapeutics. Reported deal value: $130M. Status: Pending. Sector: Biopharmaceuticals. Target headquarters context: Cambridge, Massachusetts, United States.

This page summarizes publicly available information about the transaction as of 2026-01-06. Figures and status may change as filings and press coverage update.

Day One Biopharmaceuticals , Inc. , a biopharmaceutical company dedicated to developing and commercializing targeted therapies for people of all ages with life-threatening diseases, today announced the successful close of its acquisition of Mersana Therapeutics , Inc. , following completion of all conditions of the tender offer to acquire all outstanding shares of Mersana at a price of $25 per share in cash, plus one non-tradable contingent value right per share to receive certain potential milestone payments of up to an aggregate of $30.25 per CVR in cash