GlobeNewswire Inc | Aug 20, 2021 12:30PM EDT

August 20, 2021

NEW YORK, Aug. 20, 2021 (GLOBE NEWSWIRE) -- Gainey McKenna & Egleston announces that a class action lawsuit has been filed against Sesen Bio, Inc. (Sesen or the Company) (NASDAQ: SESN) in the United States District Court for the Southern District of New York on behalf of those who purchased or otherwise acquired Sesen Bio publicly traded securities between December 21, 2020 and August 17, 2021, inclusive (the Class Period).

The Complaint alleges that Defendants failed to disclose to investors: (1) that Sesen Bios clinical trial for Vicineum had more than 2,000 violations of trial protocol, including 215 classified as major; (2) that three of Sesen Bios clinical investigators were found guilty of serious noncompliance, including back-dating data; (3) that Sesen Bio had submitted the tainted data in connection with the BLA for Vicineum; (4) that Sesen Bios clinical trials showed that Vicineum leaked out into the body, leading to side effects including liver failure and liver toxicity, and increasing the risks for fatal, drug-induced liver injury; (5) that, as a result of the foregoing, the Companys BLA for Vicineum was not likely to be approved; (6) that, as a result of the foregoing, there was a reasonable likelihood that Sesen Bio would be required to conduct additional trials to support the efficacy and safety of Vicineum; and (7) that, as a result of the foregoing, Defendants positive statements about the Companys business, operations, and prospects were materially misleading and/or lacked a reasonable basis.

On December 21, 2020, the Company announced that it had submitted its Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for Vicineum for the treatment of BCG-unresponsive NMIBC. On August 13, 2021, Sesen Bio announced that the FDA declined to approve its BLA for Vicineum in its current form. The FDA provided certain recommendations specific to additional clinical/statistical data and analyses in addition to Chemistry, Manufacturing and Controls (CMC) issues pertaining to a recent pre-approval inspection and product quality. On this news, the Companys share price fell $2.80, or 57%, to close at $2.11 per share on August 13, 2021, on unusually heavy trading volume.

Then, on August 16, 2021, Sesen Bio further revealed that it appears that [the Company] will need to do a clinical trial to provide the additional efficacy and safety data necessary for the FDA to assess the benefit-risk profile, which is the basis for approval. As a result, the Company expected that it could not resubmit its BLA until 2023. On this news, the Companys share price fell $0.89, or 42%, to close at $1.22 per share on August 16, 2021, on unusually heavy trading volume.

Investors who purchased or otherwise acquired shares of Sesen during the Class Period should contact the Firm prior to the October 18, 2021 lead plaintiff motion deadline. A lead plaintiff is a representative party acting on behalf of other class members in directing the litigation. If you wish to discuss your rights or interests regarding this class action, please contact Thomas J. McKenna, Esq. or Gregory M. Egleston, Esq. of Gainey McKenna & Egleston at (212) 983-1300, or via e-mail at tjmckenna@gme-law.com or gegleston@gme-law.com.

Please visit our website at http://www.gme-law.com for more information about the firm.