What are the possible causes of such a severe adverse reaction of the organism of the volunteers in the case of TGN1412?

To date, we have not been able to specifically identify the exact cause of the health injury suffered by the volunteers from the UK. The identification of the cause will be subject of cooperation among the regulatory drug authorities, in which our Institute has been involved. The nature of the tested substance and the reported reaction suggest possible interference with the immunological mechanisms which is difficult to anticipate on the basis of the results of safety tests in animals and which may, rather rapidly, induce a dramatic change in the state of health.