VT-111 is being developed as a therapeutic to prevent damage due to inflammation, in particular inflammation associated with the placement of a cardiac stent and inflammation caused by solid organ transplantation.  As Viron's lead candidate, it is the first example of a viral anti-inflammatory protein being successfully adapted into a therapeutic for the treatment of human disease.

VT-111 is a 55 kDa secreted glycoprotein belonging to a superfamily of proteins called SERPINS, which share a general structure and mechanism for proteinase inhibition ^(1,2).  VT-111 is an extremely potent inhibitor of monocyte migration during vascular inflammation at doses much lower (in µg/kg doses) than most biologics on the market today. VT-111 dramatically reduces leukocyte recruitment to sites of inflammation at low doses in vivo and has demonstrated efficacy in more than 40 animal models of disease including those for angioplasty, stent placement, cardiovascular bypass surgery and solid organ (heart and kidney) transplantation. Viron recently identified the mechanism of action of VT-111 and found that the protein acts through the uPA/uPAR pathway, which is known to be a critical component of monocyte migration through vascular endothelium into inflamed tissue.

VT-111 has demonstrated a favorable safety profile in two clinical trials. In 2010, Viron completed manufacturing scale-up for late stage clinical trials and market launch.  The new manufacturing process with improved yield is expected to achieve gross profit margins of over 90% even at the current 200L scale.  This optimized manufacturing process has improved the drug characteristics (extended PK) which has provided a number of new IP opportunities (new composition of matter) that extend market exclusivity for the program. The optimized product, VT-111a, will enter a Phase 2b study in 2011 in patients receiving cardiovascular stents, following on the successful Phase 2a study in that same patient population.