Abstract 7253: Oncolytic virus therapy with two-factor authentication shows robust safety and efficacy in liver cancer

Abstract

Abstract Background: Humane Genomics is pioneering multi-factored authenticated oncolytic virotherapy (OVT) using glycoprotein receptor matching and aptazyme technology to positively control replication in cytoplasm. Using VSV as a platform the OVTs show excellent safety and remain highly lytic. Sindbis virus glycoprotein was mutated to eliminate natural infectivity and retargeted to GPC3 with a codon optimized nanobody. An aptazyme was used to regulate viral replication. As far as we are aware, this was the first report of a functional ON switch using a cancer biomarker. Methods: 293T cells were used for virus rescue and titration by TCID50. Identity was confirmed by Nanopore sequencing. We evaluated safety on off-target SK-Hep-1 and NCI-H28 cell lines, and efficacy on target HepG2 and patient derived HB17 cells. Cell health and GFP was measured at multiple timepoints up to 72 hours. Results: Safety testing of HGI498 on SK-Hep-1 (GPC3 negative) and NCI-H28 (GPC3 negative, biomarker negative) showed no virus induced cell cytopathic effects in a range of 0.01 ≤ MOI ≤1. HGI498’s efficacy testing on HepG2 and HB17 showed tumor cytotoxicity at MOI 0.01 (p<0.001). Endpoint dilution assay showed a 159-fold and 316-fold difference between off-target NCI-H28 and on-target HepG2 and HB17, respectively. We incorporated an optimized aptazyme with the GPC3 targeted glycoprotein (HGI572), which was similarly rescued, titered, and evaluated for selectivity. HGI572 demonstrated approximately 1000-fold higher titer on target HepG2 and HB17 cells than off-target cells. Initial in vivo MTD study shows that both HGI498 and HGI572 are well tolerated, and are currently being investigated in vivo for efficacy on Hep3B in NSG mice. HGI498 has shown no seroprevalence (in vitro) and is stable at cryostorage for a minimum of 11 months. Conclusion: We have successfully engineered a two-factor authentication enabled OVT to address an unmet need for a therapy for liver cancer. As far as we are aware, this is the first report of an ON switch using a cancer protein to control viral replication, and the ON/OFF control is the highest to date. Citation Format: Chad M. Moles, Peter Weijmarshausen, Rupsa Basu, Brenda Ho, Manal Farhat, Taylor Flaat, Bruce F. Smith, Michael Whitt, Sarah E. Woodfield, Sanjeev A. Vasudevan. Oncolytic virus therapy with two-factor authentication shows robust safety and efficacy in liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7253.