Mersana Therapeutics Acquired by Day One Biopharmaceuticals; Bain Capital Exits Stake

summarizeSummary

Bain Capital's Schedule 13D/A confirms the completion of Mersana Therapeutics' acquisition by Day One Biopharmaceuticals, with all shares converted into the tender offer price and contingent value rights.

check_boxKey Events

• Merger Completed

  Day One Biopharmaceuticals, Inc. has completed its acquisition of Mersana Therapeutics, Inc., making Mersana a wholly-owned subsidiary.

• Shares Converted

  All shares of Mersana Therapeutics common stock were converted into the tender offer price of $25.00 cash per share plus a contingent value right (CVR) potentially worth up to $30.25 per share.

• Bain Capital Exits Position

  The reporting persons, including Bain Capital Life Sciences Fund II, L.P., ceased to hold any shares of Mersana Therapeutics following the merger.

• Director Resignation

  Dr. Hack resigned as a director of Mersana Therapeutics, effective upon the completion of the merger.

auto_awesomeAnalysis

This Schedule 13D/A filing by Bain Capital confirms the completion of the acquisition of Mersana Therapeutics by Day One Biopharmaceuticals. As of January 6, 2026, Mersana Therapeutics has become a direct wholly-owned subsidiary of Day One Biopharmaceuticals. All outstanding shares of Mersana Therapeutics common stock were converted into the right to receive the tender offer price, which included $25.00 in cash per share plus one non-tradeable contingent value right (CVR) potentially worth up to an additional $30.25 per share. This event marks the end of Mersana Therapeutics as an independent publicly traded entity, and Bain Capital, a significant investor, has fully exited its position. The resignation of Dr. Hack as a director is a direct consequence of the merger's completion.