Xenikos B.V.'s T-Guard, a mAb-toxin fusion protein that blocks activation of T cells associated with graft-versus-host disease, is being developed to provide faster symptom relief and better safety than high-dose corticosteroids now used in GvHD patients who have failed first-line treatment.

Graft-versus-host disease occurs when T cells in allogeneic stem cell transplants begin attacking the host's tissues. These T cells activate additional immune system cells such as monocytes and natural killer (NK) T cells, resulting in damage to the epithelial cells of the skin, liver and gut.