CGT are composed of a diverse group of medicinal products. Cell therapies (including ex vivo gene therapies) involve the transfer of cells with a relevant function into the patient. Cells can have different origins, i.e., human (autologous or allogeneic), different differentiation stages, i.e., stem cells or differentiated cells, and can be genetically modified to exert the intended therapeutic effect. In genetically modified cell therapy, a functional transgene is transfected into cells ex vivo using viral (for example, lentiviruses) or nonviral (e.g., electroporation) vectors. Next, the modified cells are administered to the patient where the transgene will promote a therapeutic effect. Examples of these therapies include chimeric antigen receptor (CAR) T cells and genetically modified human stem cells (HSCs).
This article highlights the importance of measuring potency for cell and gene therapies.