( /p> -- Six of 9 patients in one treatm...)Interim Results Presented at EASL from PROVE 1 Clinical Trial of,Investigational Drug Telaprevir in Patients with Genotype 1,Hepatitis C,Health

-- Six of 9 patients in one treatment arm who completed 12 weeks of treatment, and who had achieved an RVR as defined by the study protocol ((less than)10 IU/mL), continued to have undetectable HCV RNA 20 weeks after stopping all treatment ("SVR20").

-- The treatment discontinuation rate due to adverse events through 12 weeks was 11% in telaprevir arms and 3% in the control arm. Rash, gastrointestinal events and anemia were the most common events leading to discontinuation in the telaprevir arms.

"These interim results support our approach to evaluating telaprevir-based regimens of differing durations in our Phase 2 program. The results of the 12-week duration regimen provide a level of confidence in the shorter duration approach, and we look forward to safety and antiviral data, including SVR data, from the 24-week telaprevir-based regimens," said John Alam, M.D., Executive Vice President, Medicines Development, and Chief Medical Officer of Vertex. "The information from PROVE 1 and PROVE 2 should allow us to design optimized durations and regimens for Phase 3 development."

PROVE 1 and PROVE 2 represent two of three large, ongoing clinical studies of telaprevir. In aggregrate, the three studies are designed in part to evaluate the safety and antiviral activity of different durations of telaprevir-based therapy in genotype-1 infected HCV treatment-naive and treatment-failure patients, both with and without ribavirin. Taken together, the PROVE studies are expected to provide information to optimize the treatment duration and treatment regimen for telaprevir-based therapy.

PROVE 1: Implications for Clinical Development and Registration Path

Vertex today discussed the potential implications that the new information from PROVE 1 has for future clinical development of telaprevir. Vertex stated its intention to consider evaluation of treatment regimens that would include telaprevir in combination with peg-IFN and RBV, and depending
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