Chimeric antigen receptor (CAR) T cell therapy involves engineering the patient’s own immune cells to recognise and attack a specific tumour. It has shown long-term promise in patients with advanced disease. As the therapy works by harnessing the immune system it is crucial that there is no off-target activity that could promote an inappropriate immune response and be very dangerous for the patient.
Retrogenix’s standard approach for specificity screening of CAR T cells initially focused solely on the single chain variable fragment (scFv) that will ultimately be engineered onto the T cells. However, we have now also developed a methodology for labelling and screening the whole CAR T cells themselves. This can provide even greater confidence in the specificity of the therapy. It also provides further support for IND submissions.
Screen scFvs or whole CAR T cells
Retrogenix has two approaches for off-target screening of CAR T cells:
- Screen the antigen recognition element – the scFv
- Screen whole engineered CAR T cells
Early specificity screening helps select the right scFvs in order to maximise the chances of producing the most promising potential CAR T therapy. This can be followed later by screening of the whole engineered T cell to provide a more physiological assessment of off-target liability.