Sesen Bio Stockholders Approve Merger With Carisma Therapeutics; Declares Special Dividend In The Aggregate Of $75M, Expected To Result In $0.36 Per Share To All Common Stockholders

Declares Special Dividend in the Aggregate of $75 Million

Approximately 88% Voted in Favor of the Merger at the Special Meeting

Merger on Track to Close on March 7, 2023

Sesen Bio, Inc. (NASDAQ:SESN) ("Sesen Bio" or the "Company"), today announced that its stockholders have voted to approve all proposals, including the pending merger with Carisma Therapeutics Inc. ("Carisma"), at the Company's Special Meeting of Stockholders (the "Special Meeting") held earlier today.

Dr. Thomas Cannell, President and Chief Executive Officer of Sesen Bio, said, "We are pleased with the outcome of today's Special Meeting and thank our stockholders for their support of the merger with Carisma. The fact that over 88% of stockholders voted in favor of the merger provides further confidence that our thorough strategic process maximizes value for stockholders. Throughout the process, we have been actively conserving capital and we are closing the merger with approximately $150 million in cash and cash equivalents, of which roughly half will go directly to Sesen Bio stockholders in the form of a $75 million special dividend we announced today, with the remainder going toward funding the combined company."

"Looking ahead, our stockholders are positioned to benefit from the upside potential of ownership in the combined company, as well as the CVR, which provides additional potential cash upside from any sale of Sesen Bio's legacy assets, including Vicineum, and from the potential $30 million milestone payment under the Roche Asset Purchase Agreement. We look forward to completing the merger and realizing our bright future with Carisma."

Based on a preliminary count of the voting results from today's meeting of stockholders, more than 88% of the votes cast were voted in favor of Proposal No. 1 to approve the issuance of Sesen Bio common stock to Carisma stockholders in the merger and approximately 86% of votes were cast in favor of Proposal No. 2, representing more than 57% of outstanding shares of Sesen Bio common stock, to approve the amendment to Sesen Bio's certificate of incorporation to effect a reverse stock split of outstanding shares of Sesen Bio common stock at a ratio of 1-for-20. The approval of Proposal Nos. 1 and 2 was needed to complete the merger. Sesen Bio currently anticipates that the reverse stock split will become effective after trading hours on March 7, 2023, such that trading of post-split Carisma ("CARM") common stock will commence on March 8, 2023.

The merger is expected to close on March 7, 2023, subject to customary closing conditions. The final voting results for the company's special meeting will be disclosed in a Form 8-K filed with the Securities and Exchange Commission (the "SEC") and will also be available at https://ir.sesenbio.com/, after certification by the company's inspector of elections.

In connection with the transaction, the Sesen Bio Board of Directors has declared a one-time, special cash dividend of $75 million. Based on the current number of shares outstanding, the special cash dividend is expected to result in $0.361 per share to all common stockholders of record as of the close of business on March 7, 2023, payable no later than March 10, 2023.

Sesen Bio stockholders of record will also be issued one Contingent Value Right (CVR) for each outstanding share of Sesen Bio common stock, representing the right to receive any potential proceeds from the sale of Vicineum and Sesen Bio's preclinical assets prior to March 31, 2027 and any proceeds from the potential milestone payment under the Roche Asset Purchase Agreement. The issuance of the special cash dividend and CVR remain contingent on the closing of the approved transaction.

Additional information about the reverse stock split can be found in the Company's definitive proxy statement filed with the SEC on January 19, 2023, which is available at the SEC's website, www.sec.gov, and at the company's website, www.sesenbio.com.

SVB Securities is acting as exclusive financial advisor to Sesen Bio for the transaction and Hogan Lovells US LLP is serving as its legal counsel.