Earlier this month eight healthy volunteers in a phase I trial received a T cell agonist at Parexel's clinical pharmacology research unit at Northwick Park Hospital, London.1 The six men who received the active component rapidly developed catastrophic multisystem failure; the remaining two, who received a placebo, were unharmed. At the time of going to press, two remained in a critical condition. This was the first human trial of TeGenero's TGN1412, a new humanised monoclonal superagonist of the CD28 T cell surface receptor,2 designed to mitigate autoimmune and immunodeficiency disease.

This allegedly unprecedented event in clinical research represents a very human tragedy, one which will probably change for ever the face of clinical drug development and testing, and one which gives us the opportunity to learn many valuable lessons. A system based approach to learning is more likely to generate useful outcomes than one that is narrowly explanatory and blame oriented. Yet health care has been learning this lesson slowly and painfully.3 Nobody should be surprised that this disaster happened: even rare …