Cell and Gene Therapy Catapult and the MHRA collaborate on adeno-associated virus reference material pilot study to support development of gene therapies

The adeno-associated virus serotype 2 (AAV2) standard material was produced at the Cell and Gene Therapy Catapult’s (CGT Catapult) Braintree Manufacturing Innovation Centre, in collaboration with the Medicines and Healthcare products Regulatory Agency (MHRA). The AAV2 was sent to multiple laboratories in the UK, to evaluate how analytical methods used to assess AAV2 varies between laboratories.


AAVs are approved for human use to treat genetic diseases. They make ideal gene therapy vectors because they do not usually cause any illness on their own and their genetic material can be relatively easily replaced with genes that encode therapeutic human proteins.

Reference materials are crucial for the development of AAVs as they provide benchmarks against which newly made AAVs can be compared, and they can be used to evaluate new analytical methods. However, researchers and companies working with AAVs currently rely heavily on reference materials produced over a decade ago and this supply is rapidly running out.

Scientists working at the MHRA’s South Mimms site approached the CGT Catapult to help conduct a research project to see how analytical methods used by leading AAV researchers vary between labs. For this project, they needed a standard material that could be supplied to multiple sites. The AAV2 material was produced by CGT Catapult staff on a new platform at its Braintree Manufacturing Innovation Centre. The AAV platform used to produce this material was transferred from the CGT Catapult’s viral vector team in London.

The AAV produced was sent out to multiple laboratories. When the MHRA analysed the data generated from these various research labs, they found that the analytical methods employed across the different sites varied significantly, sometimes by two orders of magnitude. This study reinforces the importance of reference standards for research and shows that further improvement and standardisation of AAV analytical methods is essential to ensure consistency across different labs.

Matthew Durdy, Chief Executive of the Cell and Gene Therapy Catapult said: “This collaboration is an example of how the cell and gene therapy sector is responding to challenges that may slow the growth of the industry. In this case, working together with MHRA, it has been possible to identify how further standardisation is needed in the analytical methods that assess AAVs, an important material used in the research and development of many advanced therapies.”

Dr Marc Bailey, Chief Science and Innovation Officer at the MHRA said: “AAVs play a vital role in the delivery of cell and gene therapies, which have the potential to slow, stop or even cure genetic diseases for patients and their families.

“However, for research and development to be accurate and replicable, it is crucial that the quality of biological products such as AAVs are consistent across every batch around the world.

“This latest research reinforces the importance of establishing and ensuring standards for clinical research so that clinicians and the patients they support can be confident in the quality of the AAVs they are using from the lab to the health centre.”

This project was made possible through a grant from the Regulators Pioneer Fund, which enables UK regulators and local authorities to help create a UK regulatory environment that supports innovation and business development in the UK.

About the MHRA

The Medicines and Healthcare products Regulatory Agency (MHRA) regulates medicines, medical devices, and blood components for transfusion in the UK. The MHRA is responsible for making sure these products meet set standards for safety, quality, and effectiveness. The MHRA is an Executive Agency of the Department of Health and Social Care. For more information visit gov.uk/mhra

National Institute of Biological Standards and Control (NIBSC) standards, from the MHRA, are available globally to set the quality of biological medicines. MHRA develops and produces over 90% of the WHO International Standards in use around the world. The MHRA also offers NIBSC contract and control testing services.