Y-mAbs Therapeutics Agrees to Acquisition by SERB Pharmaceuticals

New York – August 5, 2025 – Cooley advised Y-mAbs Therapeutics, a commercial-stage biopharmaceutical company focused on the development and commercialization of antibody-based therapeutics for the treatment of cancer, on its definitive merger agreement with SERB Pharmaceuticals. Under the agreement, SERB will acquire Y-mAbs, including its lead commercial oncology asset, DANYELZA, in an all-cash transaction representing an equity value of approximately $412 million.

As part of the transaction, SERB will commence an all-cash tender offer to purchase all outstanding shares of Y-mAbs common stock. Holders of Y-mAbs common stock will receive $8.60 per share in cash, representing a premium of approximately 105% to the company’s closing share price on August 4, 2025, the last full trading day prior to the transaction announcement.

Lawyers Bill Sorabella, Bill Roegge, Div Gupta, Sarah Sellers and Ryan Genkin led the Cooley team advising Y-mAbs.

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