InsideArbitrage Event Driven Monitor – November 14, 2025

Merger Arbitrage

1. MRSN: The acquisition of Mersana Therapeutics, Inc. (MRSN) by Day One Biopharmaceuticals, Inc. (DAWN) for a closing value of $129 million. Day One would acquire Mersana, through a tender offer, for upfront consideration of $25 per share in cash plus up to an aggregate of $30.25 per share in cash potentially payable under contingent value rights (CVRs) upon the achievement of certain clinical development, regulatory and commercial milestones related to Emi-Le, Mersana’s B7-H4-directed Dolasynthen ADC, and upon the achievement of a certain milestone pursuant to an existing Mersana collaboration to be issued in the proposed acquisition. The upfront cash payment of $25 per share represents a premium of 181.85% from the stock’s last close. (Press Release)
2. GES: Guess (GES) announced that on November 11, the merger received antitrust clearance from the Republic of Cyprus.
3. LVTX: LAVA Therapeutics (LVTX) announced that the tender offer expired on November 12, 2025. The Depositary and Paying Agent advised XOMA Royalty (XOMA) that approximately 22.88 million shares, representing roughly 86.9% of the outstanding Shares, were validly tendered.

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