Fenwick Represents Day One in $285 Million Acquisition of Mersana Therapeutics

Fenwick is representing Day One Biopharmaceuticals, Inc. (Nasdaq: DAWN), a biopharmaceutical company dedicated to developing and commercializing targeted therapies for people of all ages with life-threatening diseases, in its acquisition of Mersana Therapeutics, a clinical-stage biopharmaceutical company.

The acquisition of Mersana Therapeutics expands Day One’s portfolio with novel antibody-drug conjugate (ADC) emiltatug ledadotin (Emi-Le). Under the terms of the definitive merger agreement, Day One will promptly commence a tender offer to acquire all of the outstanding shares of Mersana common stock at a price of $25 per share in cash at closing plus one non-tradable CVR per share to receive certain potential milestone payments of up to an aggregate of $30.25 per CVR in cash, for total consideration of up to $55.25 per share in cash, representing a total deal value of up to approximately $285 million. The transaction is expected to close by the end of January 2026, subject to receipt of applicable regulatory approvals and the satisfaction of other customary conditions. More information can be obtained from Day One’s announcement.

The Fenwick transaction team includes corporate partners Effie Toshav, David Michaels, Rob Freedman and Julia Forbess, associates Rob O’Connor, Arielle Trapp, Zoe Zhang, Christian Choi, Meg Moloney, Ankeet Ball, Phillip Craig, Kale Olmstead and law clerk Morgan Martin; technology transactions partner Stefano Quintini, counsel Amy Manning and associates Jennifer Yoon and Phillip Yin; executive compensation partner Marshall Mort and associates Jonathan Stephenson and Rachel Coffey; tax partner William Skinner; and antitrust partner Steve Albertson and associate Susan Lee.