NG-641: Targeting Cancer-Associated Fibroblasts with T-SIGn Oncolytic Virus for Human Carcinomas

NG-641 is an enhanced version of the adenovirus enadenotucirev, engineered to target the tumor microenvironment by breaking down the stromal barrier and overcoming immune suppression. This virus selectively attacks epithelial cancer cells and has been safely administered intravenously to over a hundred patients. It has been modified to produce a bi-specific T-cell activator, FAP-TAc, which recognizes fibroblast activating protein on cancer-associated fibroblasts and CD3 on T-cells, leading to the modification of the tumor environment and promoting anti-tumor immunity. The virus also produces CXCL9, CXCL10, and IFNα to attract T-cells and enhance immune responses, overcoming the challenges of poor immune cell infiltration in certain tumors.

Initial experiments demonstrated that NG-641's FAP-TAc activity is comparable to other viruses with the same transgene. The virus was found to selectively release functional FAP-TAc molecules, which were confirmed through cocultures with fibroblasts and T-cells. The production of CXCL9, CXCL10, and IFNα was validated using ELISA assays, and their functionality was assessed through various assays, including reporter cell, FACS, and cell migration tests. The activation of T-cells by FAP-TAc resulted in cytokine release and increased cytotoxicity towards fibroblasts, with IFNα further enhancing these effects. Studies with primary human tumor samples confirmed the potent activation of endogenous T-cells by the virus-produced FAP-TAc, even in the presence of a suppressive tumor microenvironment.

The research concludes that NG-641 effectively targets cancer-associated fibroblasts for T-cell mediated destruction, strongly activating endogenous T-cells to kill these fibroblasts and potentially offering a promising strategy for inducing anti-tumor immunity in patients with stromal rich tumors.