10 December 2025

CGT Catapult leads on test to boost stem cell therapies

Cell and Gene Therapy Catapult (CGT Catapult), an independent innovation and technology organisation specialising in the advancement of the cell and gene therapy industry, has established a consortium to demonstrate how safety tests that detect potentially dangerous undifferentiated residual cells, which can affect product purity, could be applied to a range of a cell therapies.   

Pluripotent stem cells (PSCs) possess the capacity to differentiate into many clinically relevant cell types. This makes them valuable for use in advanced therapies, including cell replacement and regenerative therapies, adaptive or genetically modified interventions, and targeted therapeutic approaches. However, if there are undifferentiated PSCs remaining in a therapy, these carry a risk of uncontrolled proliferation and tumour formation. To ensure patient safety and regulatory compliance, drug developers must rigorously test that their final products are free from these residual PSCs. As there is currently no universal test for this, therapy developers separately develop tests for each of their products which is costly and adds time to the therapy development process.  

To tackle this issue, the CGT Catapult has established ReCell, a 13-partner consortium that brings regulators, therapy developers, contract development and manufacturing organisations (CDMOs), and a contract research organisation (CRO) together to address this shared industry challenge. They will check if two droplet digital PCR methods can detect if residual PSCs are present in eight different therapy products, including those using neuronal, cardiac, and haematological lineages.  

One test has been developed by the CGT Catapult in partnership with the Health and Environmental Sciences Institute’s (HESI) Cell Therapy Tracking, Circulation, and Safety committee. The other test, SistemPSCcheckTM, has been developed by Sistemic and is a commercially available solution for therapy developers. 

Matthew Durdy, Chief Executive of the CGT Catapult, said: “Universal tests for residual PSCs could help accelerate the development of safe and effective cell therapies. By working together with experts from Sistemic, MHRA, and a group of leading therapy developers, we hope to demonstrate how such tests could be applied to a range of products to reduce costs, shorten development timelines, and ensure life-changing advanced therapies are safe for patients.” 

Lawrence Tallon, Chief Executive of the MHRA, said: “The science behind cell therapies is advancing quickly, opening up real hope for people living with serious and rare conditions. A universal test would help ensure these promising treatments reach patients sooner by providing a consistent, reliable way to demonstrate products are safe. 

“By joining this consortium, we're supporting practical work that will give innovators greater confidence, reduce duplication and remove unnecessary delays in development. This kind of collaboration keeps patient safety at the centre while strengthening the UK as a hub for responsible innovation in advanced treatments.” 

Jim Reid, Chairman and CEO of Sistemic Limited, said: "Cell therapies have incredible potential in a wide range of currently untreatable or difficult to treat diseases, but standardisation and industrialisation needs to happen if this goal is to be reached. The opportunity to be part of this exciting development and to work with the Cell and Gene Therapy Catapult and MHRA as well as many companies developing the therapies of the future gives Sistemic the opportunity to contribute to the establishment of a universal test and drive the development of safe PSC-based therapies." 

The consortium is made up of: Advent Bioservices, Cell and Gene Therapy Catapult, Cellistic, Curileum Discovery, the Medicines and Healthcare products Regulatory Agency (MHRA), Plasticell, Rinri Therapeutics, the Scottish National Blood Transfusion Service, Sistemic, SmartCella, StemSight, and the University of Nottingham, and Xellera Therapeutics.