Immunotherapy: opportunities, risks and future perspectives.

This review is intended to reflect upon the current status and perspectives of cell-based immunotherapy at a time when the promise of extensive pre-clinical research has been translated into encouraging clinical responses. However, some of these have also been complicated by significant adverse reactions. As the field moves towards definitive late stage trials, with a growing interest from pharmaceutical companies, we realize that novel cell therapy strategies pose questions that are familiar to traditional drug development, along with new considerations due to the potential of T cells to persist long term and to expand after adoptive transfer. These questions address the safety of the product, the efficacy, the mode of action, and the anticipation of risks. From different perspectives, we intend to address exciting opportunities and safety concerns in current concepts of cellular immunotherapy.