UK-based biotechnology firm PsiOxus Therapeutics has initiated a clinical trial with NG-641, a four transgene tumour-microenvironment modifying gene therapy, to treat cancer patients.

For the first time, a tumour-specific virus comprising four unique therapeutic transgenes is being administered to subjects.

PsiOxus chief scientific officer Dr Brian Champion said: “With NG-641, our approach of systemically delivering gene therapy vectors to turn tumour cells into drug factories is being deployed to deliver a bispecific T-cell activating protein to target cancer-associated fibroblasts (CAFs) via the fibroblast activation protein (FAP).

“This mechanism allows us to target one of the most important immunosuppressive cells in the tumour microenvironment.”

Besides the FAP-targeted T-cell activator, the cancer gene therapy delivers three other molecules to additionally recruit and activate T-cells in order to induce an anti-tumour immune response (IR).

NG-641 is, therefore, the first four transgene viral gene therapy treatments for the study of cancer in patients.

PsiOxus chief medical officer Dr Tom Lillie added: “I look forward to the opportunity to work with the rest of the PsiOxus team as we continue to develop innovative gene therapy products to treat and benefit cancer patients.”

The company noted that the Phase I STAR study is being conducted at multiple cancer centres in the US. It will assess the safety and efficacy of NG-641 in patients with solid tumours.

PsiOxus’ proprietary gene therapy platform, T-SIGn, is based on the company’s oncolytic virus enadenotucirev and delivers different combinations of therapeutic transgenes to carcinomas.

In March 2016, PsiOxus began the Octave trial of paclitaxel combined with the oncolytic virotherapy enadenotucirev to treat patients with ovarian cancer.