Sesen Bio Inc. (NASDAQ: SESN) announced the termination of clinical development for Vicineum (VB4-845), its next-generation antibody drug conjugate (ADC) for non-muscle invasive bladder cancer, following discussions with the U.S. FDA. The decision cited costs associated with conducting another Phase III study.
Drug Profile and Licensing Deal
Vicineum, developed on Sesen Bio’s targeted protein therapy platform, combines an anti-EPCAM antibody fragment with a truncated Pseudomonas Exotoxin A. In July 2020, China’s Qilu Pharmaceutical Co., Ltd licensed exclusive rights to the drug in China for $35 million, filing a bridging Phase III trial there in March 2021.
Regulatory and Market Impact
Sesen Bio received a complete response letter (CRL) from the FDA in August 2021, triggering a 70% share drop and reducing its market valuation from $1 billion to $350 million. Shares fell another 28% following the termination news, leaving the firm with a $130 million market cap. The impact on Qilu’s China plans remains unclear.-Fineline Info & Tech
