Standards Development

Scope

This document provides minimum requirements for quantifying viral vectors in term of physical titer and functional titer. It provides key considerations for general methods for viral vector quantification as well as for method selection, measurement process, data analysis, and reporting.

This document is applicable to all types of viral vectors (e.g., adeno-associated, adenovirus, retrovirus, lentivirus, herpesvirus) for therapeutic use, including their research and development. 

This document is not intended for viral vectors for non-health sectors.

Purpose

Modern and emerging biotechnology is underpinned by the ability to manipulate the genes and genomes of living system. Gene delivery systems are foundational to genome engineering. Gene delivery technology is evolving rapidly with numerous types of gene delivery systems providing a comprehensive set of tools and capability for in vitro or in vivo targeted delivery.

ISO/IS 16921consists of multiple parts to provide common understanding, guides, and analytical method for characterizing these emerging biotechnology tools.

- Part 1: Vocabulary

- Part 2: Viral vectors

- Part 3: Lipid nanoparticles

Part of this series focus on viral vector, which are engineered viruses for delivering genetic materials into cells via efficient transport of their genomes inside the cells they infect. Viral vectors are powerful molecular biology tools and have been increasingly used in broad biotechnology applications and products. Various types of viral vectors are used as advanced gene therapies, as vaccines, and as critical reagents for cellular therapies. They have also been increasingly used in genome editing applications. Viral vector titer is central to all applications. A commonly understood vocabulary for viral vector titer as well as methods for determining and reporting a titer measurement are important for the industry. This document defines terms and provides general guidance for the viral vector titer measurement, including method selection, sample preparation, measurement, qualification and validation, and data analysis and reporting.

Consensus is needed due to the current lack of consistency between terminology and data from different companies and laboratories. Transferring products from a client to a manufacturer while maintaining quality is difficult and often requires a change in methodology. Currently, companies are relying upon comparability studies, which are insufficient. Additionally, due to needed changes in methodology for the assessment and quantification gene delivery systems, historical data is often lost without proper standards.

The current system is inefficient and difficult for research and manufactures. Comparability, consistency terminology, and application of fit for purpose measurements as well as robust reporting schemes would speed up the manufacturing and development process, lower the cost, and support translation of emerging biotechnology products.