Sesen Bio’s most advanced product candidate, Vicineum, also known as VB4-845, is a locally-administered targeted fusion protein composed of an anti-epithelial cell adhesion molecule antibody fragment tethered to a truncated form of Pseudomonas exotoxin A for the treatment of non-muscle invasive bladder cancer.

On July 15, 2022, Sesen Bio made the strategic decision to voluntarily pause further development of Vicineum in the US. The decision was based on a thorough reassessment of Vicineum, which included the incremental development timeline and associated costs for an additional Phase III clinical trial, following Sesen Bio’s discussions with the US FDA.

Sesen Bio has turned its primary focus to assessing potential strategic alternatives with the goal of maximizing shareholder value. Additionally, Sesen Bio intends to seek a partner for the further development of Vicineum.