The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to VB4-845 for the treatment of bacillus Calmette-Guérin (BCG)–unresponsive, high-grade, non–muscle invasive bladder cancer. VB4-845 is currently being evaluated in a phase III registration trial—the VISTA Trial—for the treatment of patients with high-grade non–muscle invasive bladder cancer who have previously received two courses of BCG and whose disease is now BCG-unresponsive.
Enrollment is complete in the VISTA Trial and the company expects to report 12-month efficacy results in mid-2019.
VB4-845 is a next-generation antibody-drug conjugate comprised of a recombinant fusion protein that targets epithelial cell adhesion molecule (EpCAM) antigens on the surface of tumor cells to deliver a potent protein payload, Pseudomonas exotoxin A. VB4-845 is constructed with a stable, genetically engineered peptide linker to ensure the payload remains attached until it is internalized by the cancer cell, which is believed to decrease the risk of toxicity to healthy tissues, thereby improving its safety. In prior clinical trials, EpCAM has been shown to be overexpressed in non–muscle invasive bladder cancer cells with minimal to no EpCAM expression observed on normal bladder cells.
The activity of VB4-845 in BCG-unresponsive non–muscle invasive bladder cancer is also being explored at the National Cancer Institute in combination with the immune checkpoint inhibitor durvalumab.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.