CARISMA Therapeutics Inc. entered into a definitive merger agreement to acquire Sesen Bio, Inc. (NasdaqCM:SESN) from The Vanguard Group, Inc., JEC II Associates, LLC, BML Investment Partners, L.P. managed by BML Capital Management, LLC and others for approximately $190 million in a reverse merger transaction on September 20, 2022. Upon the closing of the Merger, Sesen Bio stockholders are expected to own approximately 41.7% of the combined company and Carisma stockholders are expected to own approximately 58.3% of the combined company. Immediately prior to the closing of the proposed merger, Sesen Bio stockholders of record will be issued a contingent value right (CVR) for each outstanding share of Sesen Bio common stock held by such Sesen Bio stockholder as of such date, representing the right to receive certain cash payments from proceeds received by Sesen Bio related to the Roche Asset Purchase Agreement, if any, subject to customary deductions, including for expenses and taxes. Also at the effective time, each outstanding option to purchase shares of Carisma common stock, or a Carisma option, will be assumed by Sesen Bio and will be converted into an option to purchase shares of Sesen Bio common stock, with necessary adjustments to reflect the exchange ratio. Each share of Sesen Bio common stock, each option to purchase Sesen Bio common stock, or a Sesen Bio option, and each Sesen Bio restricted stock unit convertible into Sesen Bio common stock (including both time-based restricted stock units and performance-based restricted stock units), or a Sesen Bio RSU, that is outstanding at the effective time will remain outstanding in accordance with its terms and such shares of Sesen Bio common stock, Sesen Bio options and Sesen Bio RSUs, subject to the proposed reverse stock split, will be unaffected by the merger. Following the consummation of the merger, the combined company will be headquartered in Philadelphia, Pennsylvania, pursuant to which a wholly-owned subsidiary of Sesen Bio will merge with and into Carisma, with Carisma surviving as a wholly-owned subsidiary of Sesen Bio and will be led by Steven Kelly, President and Chief Executive Officer of Carisma. The board of directors of the combined company is expected to be composed of seven members, consisting of one member designated by Sesen Bio and six members designated by Carisma. Thomas R. Cannell will be the Sesen Bio designated director following the closing of the merger, and that all other current Sesen Bio directors will resign as of the closing of the merger. Carisma will appoint the remaining directors to the Sesen Bio board of directors to fill the resulting vacancies. It is anticipated that Sanford Zweifach, Regina Hodits, Briggs Morrison, Björn Odlander and Chidozie Ugwumba will be appointed to the board of directors of the combined company by Carisma. Sanford Zweifach is expected to be appointed as chair of the board of the directors of the combined company. The combined company is expected to operate under the name Carisma Therapeutics Inc. and trade on Nasdaq under the ticker symbol “CARM”. Upon termination of the Merger Agreement under specified circumstances, Sesen Bio may be required to pay Carisma a termination fee of $7.6 million and/or reimburse Carisma's expenses up to a maximum of $1.75 million, and Carisma may be required to pay Sesen Bio a termination fee of $5.49 million and/or reimburse Sesen Bio's expenses up to a maximum of $1.75 million.

The merger is subject to approval by Sesen Bio and Carisma shareholders; the approval of the listing of additional shares of Parent Common Stock on Nasdaq shall have been obtained, Registration Statement shall have become effective; Nasdaq's approval of the listing of the shares of Sesen Bio common stock to be issued in connection with the Merger; Sesen Bio having net cash as of closing of the Merger greater than or equal to $100.0 million and other closing conditions. The merger agreement has been unanimously approved by the boards of directors of CARISMA and Sesen Bio. Concurrently with the execution of the Merger Agreement, certain stockholders of Carisma holding approximately 97.83% of the outstanding shares of Carisma capital stock have entered into support agreements with Sesen Bio and Carisma to vote, among other things, all of their shares of Carisma capital stock in favor of adoption of the Merger Agreement and certain stockholders of Sesen Bio have entered into support agreements with Sesen Bio and Carisma to vote, among other things, all of their shares of Sesen Bio common stock in favor of the Sesen Bio Voting Proposals and against any alternative acquisition proposals. On November 18, 2022, Bradley Radoff and Michael Torok and their affiliates (collectively, the “Investor Group”) disclosed beneficial ownership of 5.7% of Sesen Bio's outstanding common stock, indicated to Sesen Bio that it would not support the pending merger with Carisma on the terms set forth in the merger agreement and subsequently demanded the payment of a special cash dividend to Sesen Bio stockholders in the amount of $0.50 per share or approximately $100 million .As of January 3, 2023, the Investor Group, which own approximately 8.4% of the outstanding common stock of Sesen Bio, Inc, reiterates intent to Vote AGAINST the merger. As of January 19, 2023, the Registration Statement on Form S-4 was declared effective. On January 31, 2023, Carisma announced that it has appointed Padmanee Sharma to its Scientific Advisory Board. Sesen Bio, Inc. stockholders have voted to approve all proposals, including the pending merger with Carisma Therapeutics Inc. at the Company's Special Meeting of Stockholders held on March 2, 2023. The merger is expected to close in the next three to four months. As of December 12, 2022, the merger is expected to close in the next one to two months. As of December 29, 2022, the companies amended the merger agreement, and the merger is expected to close in the first quarter of 2023. As of March 2, 2023, The merger is expected to close on March 7, 2023, subject to customary closing conditions. Carisma expects to use approximately $28 million to $35 million of the expected cash balances of the combined company as of the closing of the merger for the advancement of CT-0525, which is significantly more than the amount allocated for CT-1119 or CT-0729.

SVB Securities is acting as exclusive financial advisor to Sesen Bio for the transaction and Steve Abrams and Jessica A. Bisignano of Hogan Lovells US LLP serving as its legal counsels. Evercore Group LLC is serving as lead financial advisor to Carisma for the transaction and BofA Securities, Inc. is also serving as financial advisor to Carisma for the transaction. Brian Johnson, Chris Barnstable-Brown, Hal Leibowitz, Liz Graffeo, Julie Hogan Rodgers, Kim Wethly, Scott Kilgore, Ciara Baker, Steven Barrett, Bruce Manheim, Mat Trachok and Meghan Walsh of Wilmer Cutler Pickering Hale and Dorr LLP serving as legal counsels to Carisma. BofA Securities, Inc. and Evercore Group L.L.C. are serving as co-placement agents for Carisma's concurrent financing and Shearman & Sterling LLP is serving as the placement agents' legal counsel. Sesen Bio has received an opinion of SVB Securities LLC. MacKenzie Partners, Inc. acted as information agent to Sesen Bio in the transaction for a fee of $20,000. SVB Securities LLC and Hogan Lovells US LLP acted as Due diligence Providers to Sesen Bio and and Wilmer Cutler Pickering Hale and Dorr LLP acted as Due diligence Provider to CARISMA. In connection with SVB Securities' services as financial advisor to Sesen Bio, Sesen Bio has agreed to pay SVB Securities an aggregate fee of $2.5 million, $750,000 of which became payable upon the rendering by SVB Securities of the opinion on September 20, 2022 and the remainder of which is payable contingent upon consummation of the merger.

CARISMA Therapeutics Inc. completed the acquisition of Sesen Bio, Inc. (NasdaqCM:SESN) from The Vanguard Group, Inc., JEC II Associates, LLC, BML Investment Partners, L.P. managed by BML Capital Management, LLC and others in a reverse merger transaction on March 7, 2023. The combined company will operate under the name Carisma Therapeutics Inc. and shares of its common stock will commence trading under the ticker symbol "CARM" on March 8, 2023 on the Nasdaq Capital Market. Wilson Sonsini Goodrich & Rosati, P.C. acted as legal advisor to the shareholders of Sesen Bio, Inc.