March 14, 2006

Enzo Therapeutics has initiated a Phase II clinical trial to evaluate its immunomodulatory candidate drug EGS21 as a therapeutic for managing Crohn's disease. A Phase I safety trial of EGS21 was successfully concluded last year.

The study is based on promising preclinical studies in animal model systems. The results of these studies demonstrated that EGS21 acts on immune regulatory (NKT) cells and therefore could impact the immune response in the body by modulating its function and adjusting it to a normal state.

The administration of EGS21 to animals with experimental allergic colitis resulted in marked alleviation of disease symptoms, with a significant improvement of the macroscopic and microscopic colitis scores in those mice that received the candidate drug compared to placebo. Alleviation of colitis symptoms by EGS21 treatment was associated in animal studies with a significant increase of intrahepatic CD8+ T cell trapping (peripheral/intrahepatic CD4+/CD8+ ratio increased by 68% in the control group compared to placebo animals). The beneficial effect of EGS21 on colitis was associated with a 17 percent increase of the intrahepatic NKT cell number and a 9 percent decrease of the peripheral/intrahepatic NKT cell ratio.