Telaprevir Presentations at the 59th AASLD Meeting to Feature SVR Data in Treatment-Naive and Treatment-Failure Genotype 1 HCV Patients, and Clinical

Vertex Pharmaceuticals Incorporated (NASDAQ: VRTX) today announced that key data on sustained viral response (SVR) rates in both treatment-naïve and treatment-failure genotype 1 hepatitis C (HCV) patients who received telaprevir-based treatment regimens will be presented at the 59^th Annual Meeting of the American Association for the Study of Liver Disease (AASLD), October 31 – November 4, 2008 in San Francisco. In addition, week 4 and week 12 data from the C208 study exploring a twice-daily telaprevir dosing regimen in 160 genotype 1 HCV patients will be presented. A total of six abstracts related to Vertex’s HCV protease inhibitor telaprevir clinical program were accepted for presentation. The abstracts are being published today and will be available online at the AASLD website (www.aasld.org). Vertex is developing telaprevir in collaboration with Tibotec.

Telaprevir-Based Therapy in Treatment-Failure HCV Patients

PROVE 3 Interim Analysis

“A Phase 2b Study of Telaprevir with Peginterferon-Alfa-2a and Ribavirin in Hepatitis C Genotype 1 Null and Partial Responders and Relapsers Following a Prior Course of Peginterferon-Alfa-2a/b and Ribavirin Therapy: PROVE 3 Interim Results” will be presented in an oral session on Tuesday, November 4 at 11:30 a.m. PST. The authors of the study are J. G. McHutchison, M. L. Shiffman, N. Terrault, M. P. Manns, A.M. Di Bisceglie, I. M. Jacobson, N. H. Afdhal, E. J. Heathcote, S. Zeuzem, H. W. Reesink, S. George, N. Adda and A. J. Muir.

Study 107 Interim Analysis

“A Study of Telaprevir Combined with Peginterferon-Alfa-2a and Ribavirin in Subjects with Well-Documented Non-Response or Relapse after Previous Peginterferon-Alfa-2a and Ribavirin Treatment: Interim Analysis” will be presented at a poster session on Tuesday, November 4 from 8:00 a.m. to 12:30 p.m. PST. The authors of the study are M. L. Shiffman, T. Berg, F. F. Poordad, J. Bronowicki, A. J. Muir, S. C. Gordon, S. George, N. Adda and J. G. McHutchison.

Telaprevir-Based Therapy in Treatment-Naïve HCV Patients

PROVE 2 Final Results

“Telaprevir in Combination with Peginterferon-Alfa-2a with or without Ribavirin in the Treatment of Chronic Hepatitis C: Final Results of the PROVE 2 Study” will be presented in an oral session on Tuesday, November 4 at 9:30 a.m. PST. The authors of the study are S. Zeuzem, C. Hezode, P. Ferenci, G. M. Dusheiko, K. Alves, L. Bengtsson, S. Gharakhanian, R. Kauffman, J. Alam and J. Pawlotsky.

C208 Study Interim Analysis – Twice-Daily Telaprevir Exploration

“Phase 2 Study of Telaprevir Administered q8h or q12h with Peginterferon-Alfa-2a or -Alfa-2b and Ribavirin in Treatment-Naïve Subjects with Genotype 1 Hepatitis C: Week 4 Interim Results” will be presented at a poster session on Tuesday, November 4 from 8:00 a.m. to 12:30 p.m. PST. The authors of the study are X. Forns, P. Marcellin, T. Goeser, P. Ferenci, F. Nevens, G. Carosi, J. P. Drenth, K. De Backer, R. van Heeswijk, T. J. Vangeneugden, G. Picchio and M. Beumont-Mauviel.

Additional Telaprevir Abstracts at AASLD

“Viral Responses in African-Americans, Latinos and Caucasians in the US Phase 2 Study (PROVE 1) of Telaprevir with Peginterferon Alfa-2a and Ribavirin in Treatment-Naïve Genotype 1-infected Subjects with Hepatitis C” will be presented at a poster session on Tuesday, November 4 from 8:00 a.m. to 12:30 p.m. PST. The authors of the study are A. J. Muir, E. J. Lawitz, J. G. McHutchison, S. C. Gordon, I. M. Jacobson, B. Adiwijaya, L. Bengtsson, L. McNair and M. Rodriguez-Torres.

“No Compensatory Fitness Mutations Selected in NS3/4A Protease Cleavage Sites During Treatment with Telaprevir, Peg-IFN-Alfa-2a, and Ribavirin in Phase II Studies of Treatment-Naïve HCV Genotype 1-Infected Patients” will be presented at a poster session on Tuesday, November 4 from 8:00 a.m. to 12:30 p.m. PST. The authors of the study are E. Z. Zhang, D. J. Bartels, J. Sullivan, M. Marcial, J. Dorrian, A. Tigges, A. D. Kwong and T. L. Kieffer.

About Telaprevir

Telaprevir (VX-950) is an investigational oral inhibitor of HCV protease, an enzyme essential for viral replication, and is one of the most advanced investigational antiviral agents in development that specifically targets HCV. Telaprevir is in Phase 3 clinical trials in treatment-naïve and treatment-failure patients.

About Hepatitis C

Hepatitis C is a liver disease caused by the hepatitis C virus, which is found in the blood of people with the disease. HCV, a serious public health concern affecting 3.4 million individuals in the United States, is spread through direct contact with the blood of infected people. Though many people with HCV infection may not experience symptoms, others may have symptoms such as jaundice, abdominal pain, fatigue and fever. Chronic HCV significantly increases a person’s risk for developing long-term infection, chronic liver disease, cirrhosis or death. The burden of liver disease associated with HCV infection is increasing, and current therapies typically provide sustained benefit in less than half of patients with genotype 1 HCV, the most common strain of the virus. As many as 250,000 patients in the United States have received at least one course of treatment with pegylated interferon and ribavirin but have not achieved sustained virologic response (SVR). Patients who have failed interferon-based treatment typically have few or no available treatment options, and are at risk for progressive liver disease. In a recent study, the risk of liver failure, cancer or death following unsuccessful HCV treatment was 23% after 4 years, and 43% after 8 years. ^(1).

About Vertex

Vertex Pharmaceuticals Incorporated is a global biotechnology company committed to the discovery and development of breakthrough small molecule drugs for serious diseases. The Company’s strategy is to commercialize its products both independently and in collaboration with major pharmaceutical companies. Vertex’s product pipeline is focused on viral diseases, inflammation, autoimmune diseases, cancer, pain and cystic fibrosis. Vertex co-discovered the HIV protease inhibitor, Lexiva, with GlaxoSmithKline.

Lexiva is a registered trademark of the GlaxoSmithKline group of companies.

1. Veldt et al, "Sustained virologic response and clinical outcomes in patients with chronic hepatitis C and advanced fibrosis," Annals of Internal Medicine, 20 November 2007; 147: 677-684.

Safe Harbor Statement

This press release contains forward-looking statements, including statements that Vertex will present key data demonstrating the potential to achieve SVR with telaprevir-based treatment regimens and data exploring twice-daily telaprevir dosing at AASLD. While we believe the forward-looking statements contained in this press release are accurate, there are a number of factors that could cause actual events or results to differ materially from those indicated by such forward-looking statements. Those risks and uncertainties include, among other things, that the outcomes for each of the clinical trials that are the subject of the abstracts referenced in this press release may not be as favorable or may not confirm results from interim analyses conducted during those trials or the results of earlier clinical trials, that there may be varying interpretations of data produced by one or more of those clinical trials, that unexpected adverse events experienced by patients in any of these trials may slow enrollment or lead to regulatory action, and other risks listed under Risk Factors in our annual report on Form 10-K for the year ended December 31, 2007 and our quarterly reports on Form 10-Q for the quarters ended March 31, 2008 and June 30, 2008, which were filed with the Securities and Exchange Commission. We disclaim any obligation to update the information contained in this press release as new information becomes available.

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Vertex Pharmaceuticals Incorporated
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