Results from Phase IIa clinical trial evaluating VT-111 reported by Viron Therapeutics

VT-111 significantly reduces key cardiac enzymes at multiple time points after stent placement; Data presented at American Heart Association 2009 Scientific Sessions

Viron Therapeutics Inc., a biotechnology company pioneering the development of immune-modulating protein therapeutics derived from pathogens, today reported results from a Phase IIa clinical trial evaluating VT-111 (Serp-1), an anti-inflammatory protein derived from the myxoma virus. The results were presented by Dr. Jean-Claude Tardif, Director of the Research Centre at the Montreal Heart Institute, during the Scientific Sessions of the American Heart Association (AHA) 2009 conference held in Orlando, Florida from November 14 to 18. VT-111 met both primary and secondary endpoints of the trial, which was designed to evaluate the safety and biological activity of VT-111 in Acute Coronary Syndrome (ACS) patients receiving coronary stents.

"The positive safety and efficacy data from this trial provide a strong scientific rationale for moving forward with this novel drug in ACS and potentially other indications," said Dr. Tardif. "There were also no subsequent major adverse cardiac events in the high dose group, which correlates well with VT-111's impact on two prognostic cardiac biomarkers, Troponin I and CK-MB, whose predictive value have been demonstrated in other studies. It may also be possible for VT-111 to have an even greater impact if delivered in a larger dose than the low dose of 15 micrograms per kilogram ((micro)g/kg) tested in this trial."

In this double-blind, placebo-controlled Phase IIa trial, 48 patients received intravenous doses of placebo or VT-111 once daily for three days starting immediately before their stenting procedure. Subjects were then followed for three days in the hospital and returned at two weeks, four weeks, three months, and six months for evaluation of safety and a variety of inflammatory and cardiac biomarkers.

A statistically significant, dose-dependent reduction in levels of the cardiac damage biomarker Troponin I was associated with VT-111 treatment at eight, 16, 24, and 54 hours following the initial dose. The VT-111 treated patients also showed a statistically significant reduction in the cardiac damage biomarker creatine kinase myocardial biomarker (CK-MB) at eight, 16, and 24 hours. VT-111 also showed strong trends toward reducing Major Adverse Cardiac Events (MACE, a clinical endpoint comprised of myocardial infarction, revascularization, coronary artery bypass graft (CABG) or death) in the higher dose group, with no MACE events at the six month follow-up, compared to the placebo group, which had (greater than)18% MACE.

Previously published studies have shown that a reduction in the rise of Troponin I and/or CK-MB in the first 24 hours after stent placement is predictive of whether a patient will experience a subsequent clinical event.

The study showed no difference between the treatment and placebo groups for the key safety measures, including coagulation markers and adverse events. In-stent plaque area and lumen area, as assessed by intravascular ultrasound at six months, were similar for both groups. VT-111 demonstrated no drug-related adverse events and no neutralizing antibodies (low immunogenicity) in the patient population.

"This drug candidate is Viron's first successful adaptation of a viral anti-inflammatory protein into a therapeutic for the treatment of human disease, validating Viron's unique approach and our proprietary PROSPECT(TM) technology, a platform for the discovery of new immune-modulating protein therapeutics from pathogens," said James Rae, Chief Executive Officer of Viron Therapeutics. "To complement these studies in patients with vascular disease, we plan to initiate a clinical trial for VT-111 in solid organ transplantation, an area with a well-defined patient population where novel anti-inflammatory drugs have significant potential to address an unmet medical need. Our drug has demonstrated remarkable efficacy in preclinical proof-of-concept studies to support this indication."

The presentation was entitled "Viral Anti-inflammatory Treatment of Unstable Coronary Syndromes: The VT-111 Acute Coronary Syndrome Trial". A copy of Dr. Tardif's presentation is available on Viron's website, www.vironinc.com.