On vicinium

 

Vicinium, a locally administered fusion protein, is a leading candidate product of Sesen Bio (http://www.chemdrug.com/invest/), and is being developed for the treatment of high-risk NMIBC.

 

Vicinium is a humanized scFv immunotoxin targeting epithelial cell adhesion molecule (EpCAM) antigen on the surface of cancer cells. The recombinant humanized anti-EpCAM antibody scFv is coupled with Pseudomonas exotoxin A. Once combined with the expression of EpCAM in cancer cells, it will be internalized into the cytoplasm and induce apoptosis.

 

Vicinium consists of a stable genetic engineering peptide chain to ensure that exotoxin A remains attached until it is internalized by cancer cells, thereby reducing the risk of toxicity to healthy tissues (http://www.chemdrug.com/article/7/) and improving safety.

 

In the United States and the European Union, vicinium was granted orphan drug qualification in 2005 and fast-track qualification by the FDA (http://www.chemdrug.com/article/11/) in August 2018 for the treatment of NMIBC that is ineffective for BCG immunotherapy.

 

Relevant research

 

 

 

VISTA is a single-arm, 24-month, open-label, multi-center phase III study that is evaluating vicinium as a single-drug therapy for high-risk, non-responding patients with NMIBC treated with intravesical BCG immunotherapy.

 

A total of 133 patients with high-grade NMIBC in situ cancer (CIS) or papillary cancer (with or without CIS) who received BCG treatment were enrolled in the study.

 

In the study, patients were enrolled in three cohorts according to histology and adequate BCG treatment (at least 2 courses of BCG, at least 5 doses in the first course and at least 2 doses in the second course) for disease recurrence time (cohort 1: BCG treatment for refractory or relapsed CIS within 6 months; cohort 2: BCG treatment for relapsed CIS within 6-11 months; cohort 3: BCG treatment for 6 months). Internally refractory or recurrent papillary carcinoma [without CIS].

 

In the study, patients received local vicinium twice a week for six weeks, followed by six weeks a week, and then every other week for two years.