It is well acknowledged that the field of Advanced Therapy Medicinal Products is rapidly evolving leading to some gaps in the regulatory controls governing the analysis of these novel medicines.

The UK is taking an innovative and collaborative approach bringing together the ATTCs, Catapult, MHRA, British Pharmacoepoiea and NIBSC. This work aims to clarify and define best practice assisting both academic and commercial ATMP developers with accelerated access of these medicines to patients with unmet clinical needs.

Prof. John Campbell, Work Package One Lead (Manufacturing and Preparation) from the Northern Alliance led a workshop (27 February 2020) designed to focus on the use of flow cytometry to support the clinical delivery of ATMPs and to discuss ‘best practice’ in the manufacture of ATMPs. The event was held at the Royal Pharmaceutical Society of Great Britain in Central London. The day was well designed and organised due to the collaboration between Claire Brady (CGT Catapult), Dr Ryan Guest (Immetacyte), Dr Stuart Curbishly (University of Birmingham) and Dr Jacqueline Barry (CGT Catapult).

The morning session presentations were given on a variety of topics from a diverse range of experts on the key parameters for use of flow cytometry as part of quality control in the production of cell therapies. These included: Standardisation on QC for ATMPs, MHRA’s strategy for biological medicines, experiences from a trainee QPs perspective for flow cytometry for ATMP QA/QC in the clinical setting and also The National Institute for Biological Standards and Control (NIBSC) plans for standardisation and best practice using flow cytometry in ATMP manufacture. Throughout the morning intense and thought provoking discussions were held evaluating ‘best practice’ in the variety of assays and types of analysis used to QC ATMPs in their manufacture using flow cytometry.

Following this, the afternoon session used a series of exemplar products to give an overview of opportunities and challenges of using flow cytometry as a QA/QC tool. These exemplar products included dendritic cells presented by Dr Stuart Curbishley and Dr Ryan Guest on using flow cytometry as a qualitative tool in T cell based therapies. Following this, talks were given by Prof. John Campbell and Dr. Alasdair Fraser from SNBTS on analysis of macrophages and Dr Janet Glassford from the MHRA on the experiences from a MHRA Licencing Assessor’s perspective. The final speaker of the day was Dr Julian Braybrook from The LGC Group who discussed alternative bio-measurement tools and also the value of collaborating experts in this field to produce universal guidance in flow cytometry for ATMPs globally.

The event was a huge success with some key areas identified which require addressing to enable flow cytometry to be standardised for the use in ATMP manufacture. These included creating a set of best practice guidelines, holding further discussions on technology transfer and non-centralised manufacture. Other areas of minimal essential standards for flow cytometry were also highlighted. This included the production of guidance protocols to reduce operator variability and also the production of a universal standard for the collection of starting materials.