Viron Therapeutics' three drug candidates granted U.S. patents

Viron Therapeutics Inc., a biotechnology company pioneering the development of virally-derived protein therapeutics, today announced that it has been granted U.S. patents related to three of its drug candidates, VT-111, VT-346 and VT-384. These patents join a portfolio of more than 80 previously-granted patents for Viron's multiple therapeutic candidates. Viron's unique drug discovery platform identifies proteins expressed by non-human viruses that have evolved over millions of years of evolutionary selection to evade their host's immune system, endowing them with powerful immuno-modulatory and anti-inflammatory properties.

The new patent, US 7,514,405, entitled "Methods for treating transplant rejection," covers the treatment of chronic transplant rejection by administering VT-111 in combination with an immunosuppressant, such as cyclosporine. "This patent extends protection for VT-111 in transplant out to at least 2021," said Kevin Sullivan, Vice President of Business Development for Viron Therapeutics. "This provides ample time for us to unlock the commercial potential arising from upcoming organ transplant trials." Viron will pursue the transplant indication in parallel with Acute Coronary Syndromes (ACS) for VT-111, due to the significant unmet medical need in this space and the resulting rapid regulatory path forward. There are currently no therapeutic molecules targeting chronic organ rejection.

Viron's lead therapeutic candidate, VT-111, has demonstrated potent effects in preclinical suppression of chronic organ transplant rejection and, in a Phase IIa clinical trial of 48 patients, demonstrated reduced cardiac tissue damage in patients with ACS receiving cardiac stent implants. "It is remarkable to see such a small trial demonstrate such a strong, statistically significant impact in this target population," said Mr. Sullivan. "These trial results provide a compelling validation of Viron's approach to drug discovery."

Viron's second therapeutic candidate, VT-346, is a powerful inhibitor of TNF-a, the therapeutic target of Enbrel(TM), Humira(TM), Cimzia(TM) and Remicade(TM), which together share a market estimated at over $20 billion annually. In head to head testing, VT-346 has proven itself to be as much as 100 times more potent than some currently marketed therapeutics, due in part to a novel mechanism of action evolved by the original virus.

The latest patent for VT-346, US 7,585,507, entitled "Nucleic acid molecules and polypeptides for immune modulation", relates to the use of VT-346 in treating immuno-modulatory disorders characterized by inflammation, such as rheumatoid arthritis, transplant rejection, asthma and inflammatory bowel disease. The protection provided by this patent also extends out to at least 2021.

Viron recently received a Notice of Allowance from the US patent office for a patent on VT-384, a protein derived from the Yatapoxvirus that targets IL-18, a cytokine expressed at sites of chronic inflammation. This cytokine has been implicated in numerous autoimmune diseases and a variety of cancers.

"IL-18 is a target of keen interest to big Pharma, with several monoclonal antibody candidates targeting IL-18 in various stages of development. Viron's discovery platform identified this natural protein that targets IL-18, which falls outside the complicated anti-IL-18 antibody patent landscape. This has hindered development of some anti-IL-18 antibody approaches. As such, we believe the commercial prospects for VT-384 in diseases such as arthritis and COPD could be very significant," said James Rae, Chief Executive Officer of Viron Therapeutics. "These issued patents also highlight our ability to discover and develop unique therapeutics which reside within pathogens and which have had millions of years to perfect strategies to modulate the immune system."