FAP (Fibroblast activation protein-α) is a 97 kDa type II transmembrane serine protease with high tumor selectivity.

In nearly 90% of CAFs (cancer-associated fibroblasts) of epithelial malignancies, FAP is significantly overexpressed.

FAP mRNA levels are highly expressed in many tumor types, including pancreatic cancer, breast cancer, bile duct cancer, melanoma, colon cancer, head and neck cancer, esophageal cancer, lung cancer, etc., and have broad therapeutic prospects.

The widespread distribution of FAP in various cancers makes it a promising target for RDC.

Vitsgen FAP-VG-01 demonstrated great efficacy in tumor bearing animal model. Its biodistribution showed a higher (greater than 2 fold) tumor uptake; higher tumor/kidney (T/K) ratio than FAP-2286.