Defining the Probability that a Cell Therapy Will Produce a Malignancy

Cell therapies have tremendous potential, but there is a 700-pound gorilla in the room: the risk that the cells can produce malignancies. The concerns about the gorilla were highlighted by reports1,2,3 of malignant transformation in culture of the adult stem/progenitor cells referred to as mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs). These reports cast a shadow over the 100 or more clinical trials with MSCs currently being contemplated or in progress (ClinicalTrials.gov).