Mersana soars on Day One's $285 mln buyout deal

Mersana Therapeutics

13/11/2025 11:31

** Shares of drug developer Mersana Therapeutics MRSN.O more than triple to $28.39 premarket

** MRSN says Day One Biopharmaceuticals DAWN.O agrees to acquire Mersana Therapeutics in a deal that could be worth up to $285 million

** Under the agreement, Day One will pay Mersana shareholders $25/shr in cash upfront - MRSN

** Investors can receive up to an additional $30.25/ shr if certain milestones are met, bringing the total possible payout to $55.25/shr - MRSN

** Co says deal is expected to close by the end of January 2026

** MRSN develops experimental cancer drugs; Day One focuses on developing drugs for pediatric and adult cancer patients - MRSN

** Including session's move, stock down ~75% YTD

 (Reporting by Sahil Pandey in Bengaluru)

 ((Sahil.Pandey@thomsonreuters.com))