In conjunction with an oral presentation at the 45th Annual Meeting of the European Association for the Study of the Liver (EASL) in Vienna, Vertex Pharmaceuticals Incorporated announced results from a phase-1b clinical trial of the investigational oral hepatitis C virus (HCV) polymerase inhibitor, VX-222. In the trial, treatment with VX-222 for three days was well-tolerated, with all adverse events being mild to moderate in severity. Dosing with VX-222 for three days resulted in a greater than 3 log10 reduction in HCV RNA across all four of the VX-222 dosing groups. No serious adverse events or treatment discontinuations were reported in the phase-1b trial. The results from this trial support the phase-2 proof-of-concept clinical trial of VX-222 dosed in combination with Vertex's lead investigational HCV protease inhibitor telaprevir, which is expected to complete enrollment in the second quarter of 2010. Vertex retains worldwide rights to VX-222.

"In this phase-1b clinical trial, treatment with VX-222 for three days resulted in a reduction in viral load across all the dose groups studied," said Maribel Rodriguez-Torres, medical director of Fundacion de Investigacion de Diego in Puerto Rico. "This trial was designed primarily to gain important safety and viral kinetic information to enable the continued development of VX-222 as part of novel HCV combination regimens. I am pleased that additional development efforts for VX-222 are advancing, including the first trial to evaluate a two-drug regimen of VX-222 dosed in combination with the HCV protease inhibitor telaprevir."

"These early safety and efficacy results support the evaluation of VX-222 as part of novel combination regimens for the treatment of HCV, including the first phase-2 proof-of-concept clinical trial evaluating multiple telaprevir/VX-222-based combination regimens," said Robert Kauffman, senior vice president, Clinical Development and chief medical officer of Vertex Pharmaceuticals. "With VX-222, we believe we have a unique opportunity to broaden our commitment to improving patient care in hepatitis C and to strengthen our leadership position in the development of novel specifically targeted antiviral therapies for the treatment of hepatitis C."

VX-222 is a small molecule non-nucleoside inhibitor of HCV NS5B polymerase. Vertex obtained VX-222 as part of its acquisition of ViroChem Pharma Inc. in March 2009. Vertex retains worldwide rights to VX-222.

Vertex Pharmaceuticals Incorporated is a global biotechnology company committed to the discovery and development of breakthrough small molecule drugs for serious diseases.