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Updated: Jul 15, 2026
Production of Adeno-Associated Virus Vectors in Cell Stacks for Preclinical Studies in Large Animal Models
Published on: June 30, 2021
Production and release testing of ovine atadenovirus vectors
Gerald W Both1, Fiona Cameron, Anne Collins
1CSIRO Molecular and Health Technologies, North Ryde, New South Wales, Australia.
Abstract:
Gene-directed enzyme prodrug therapy (GDEPT) is an emerging approach for the treatment of cancers. A variety of viral vectors have been used to deliver genes that encode the relevant enzymes, and some have been tested in clinical trials. To ensure the potency and efficacy of such vectors and to obtain regulatory approval to administer them to humans, it is necessary to develop a suite of assays that provide quality assurance. New GDEPT vectors based on ovine atadenovirus and Escherichia coli purine nucleoside phosphorylase (PNP) have been developed for first time use in humans in a phase I trial for the treatment of prostate cancer. Here we describe methods for their production together with several quality-control assays. In particular, a functional cell killing assay was devised to measure the potency of PNP-GDEPT vectors, the principles of which could easily be adapted to other systems.
Insights
New gene-directed enzyme prodrug therapy (GDEPT) vectors using ovine atadenovirus and Escherichia coli purine nucleoside phosphorylase (PNP) show promise for prostate cancer treatment. Quality control assays, including a cell killing assay, ensure vector potency and efficacy for clinical trials.
Area of Science:
- Oncolytic Virotherapy
- Gene Therapy
- Cancer Treatment
Background:
- Gene-directed enzyme prodrug therapy (GDEPT) is an innovative cancer treatment strategy.
- Viral vectors are crucial for delivering therapeutic genes in GDEPT.
- Robust quality control assays are essential for regulatory approval and clinical application of GDEPT vectors.
Purpose of the Study:
- To describe the production methods for novel GDEPT vectors.
- To present quality-control assays for these new vectors.
- To validate a functional cell killing assay for measuring the potency of purine nucleoside phosphorylase (PNP)-GDEPT vectors.
Main Methods:
- Production of ovine atadenovirus-based vectors encoding Escherichia coli purine nucleoside phosphorylase (PNP).
- Development and implementation of several quality-control assays for vector characterization.
- Design of a functional cell killing assay to assess vector potency.
Main Results:
- Successful production of novel PNP-GDEPT vectors.
- Establishment of a suite of quality-control assays for vector assessment.
- Demonstration of a functional cell killing assay for measuring GDEPT vector potency.
Conclusions:
- The developed PNP-GDEPT vectors are suitable for human clinical trials, including a Phase I trial for prostate cancer.
- The described quality-control assays ensure the safety and efficacy of these novel GDEPT vectors.
- The principles of the functional cell killing assay can be adapted for other GDEPT systems, facilitating broader application.
