Tumor necrosis factor a (TNF-a) plays a central role in the initiation and amplification of the granulomatous inflammatory reaction seen in CD (van Deventer, 1997). Increased TNF-a is present in gut mucosa as well as in stool of patients with active CD (Braegger et al, 1992). CNI-1493 is a synthetic guanylhydrazone compound that is an inhibitor of TNF-a synthesis. A monoclonal antibody to TNF, infliximab, is now approved for treatment of CD, but not all patients respond and many who do respond eventually become refractory to this treatment as well.