UPDATE: Vertex Updates Recent Progress and Upcoming Milestones in Clinical Development Programs

Vertex's strategy in cystic fibrosis (CF) is to provide benefit to as many CF patients as possible, and to maximize the benefit for these patients, with our approved and investigational medicines. Data from Phase 3 Label-Expansion Study of Ivacaftor Monotherapy in Gating Mutations Show Statistically Significant Improvements in Lung Function In a separate press release issued today, Vertex announced data from a Phase 3 label-expansion study in people with CF who have at least one non-G551D cystic fibrosis transmembrane conductance regulator (CFTR) gating mutation that showed statistically significant improvements in lung function (percent predicted forced expiratory volume in one second; FEV1). Additional details on these data were provided in the separate press release. Based on these data, Vertex plans to submit a supplemental New Drug Application (sNDA) in the United States and a Marketing Authorization Application (MAA) variation in Europe in the second half of 2013 for the use of ivacaftor monotherapy in people with CF ages 6 and older who have at least one non-G551D CFTR gating mutation. Approximately 400 people with CF ages six and older have a non-G551D gating mutation worldwide. Continued Progress in Additional Label-Expansion Studies for Ivacaftor Monotherapy Two additional Phase 3 label-expansion studies are ongoing for ivacaftor monotherapy, including a study in people with CF ages 6 and older who have at least one copy of the R117H mutation and a study in children with CF ages 2 to 5 who have a gating mutation, including the G551D mutation. Data from the study in the R117H mutation are expected in the second half of 2013, and, pending study results, Vertex plans to submit an sNDA in early 2014 for the use of ivacaftor monotherapy in people with CF ages 6 and older who have the R117H mutation. The pharmacokinetic portion of the study in children ages 2 to 5 is complete and a dose has been selected for the 24-week dosing period, which is now underway. Data from this study are expected in mid-2014. Study of People with CF Who Have Evidence of Residual CFTR Function Enrollment is ongoing in a Phase 2 proof-of-concept study evaluating ivacaftor in people with CF who have clinical evidence of residual CFTR function. Data from this study are expected in the first half of 2014. Vertex believes that ivacaftor monotherapy may provide clinical benefit in 10 to 15 percent of the estimated 70,000 CF patients worldwide, pending results from our clinical studies and regulatory approvals. Enrollment Ongoing in Phase 3 Registration Program for VX-809 in Combination with Ivacaftor Two 24-week Phase 3 studies of VX-809 in combination with ivacaftor are ongoing in people ages 12 and older with two copies of the most common mutation in the CFTR gene, known as F508del. The company expects to complete enrollment in these studies in the second half of 2013. Vertex plans to submit a New Drug Application in the United States for this combination treatment in 2014, pending study results. Worldwide, nearly half of people with CF have two copies of the F508del mutation. The pivotal program for VX-809 in combination with ivacaftor also includes an evaluation of this combination in people with one copy (heterozygous) of the F508del mutation and a pharmacokinetic and safety evaluation of this combination in children ages 6 to 11 with two copies of the F508del mutation. Enrollment in these additional studies is expected to begin in the second half of 2013. Advancing Multiple First- and Second-Generation Correctors VX-661: At the European Cystic Fibrosis Society (ECFS) conference in June, Vertex presented data from a Phase 2 study of VX-661 in combination with ivacaftor. Additional details on these data are available in a press release issued on June 5, 2013. Vertex is preparing to begin Phase 2 evaluation of a 4-week regimen of VX-661 in combination with ivacaftor in people with one copy of the F508del mutation and one copy of the G551D mutation. This is the first proof-of-concept study of a combination of a corrector and ivacaftor in people with the G551D mutation. This exploratory evaluation is based on in vitro data presented at ECFS by Vertex researchers that showed increased chloride transport in human bronchial epithelial cells with one copy of the F508del mutation and one copy of the G551D mutation after treatment with a corrector and ivacaftor, as compared to the use of ivacaftor alone. Vertex's strategy is to evaluate multiple first-generation correctors, including VX-661 and VX-983, in combination with ivacaftor to identify regimens that may provide benefit to people with the F508del mutation. Second-generation Correctors: Vertex has an active research program focused on second-generation correctors that could be used as part of a future dual-corrector regimen in combination with ivacaftor in people with one or two copies of the F508del mutation. Vertex's goal is to advance a second-generation corrector into clinical development by the end of 2014. The proposed use of a dual-corrector combination regimen is supported by in vitro data presented at ECFS that showed a combination of two correctors and ivacaftor increased chloride transport in human bronchial epithelial cells with one or two copies of the F508del mutation, as compared to the use of a single corrector in combination with ivacaftor. Hepatitis C Vertex's strategy in hepatitis C is to develop new all-oral treatment regimens of 12 weeks or less in duration with a goal of providing a high viral cure rate and improved tolerability over currently available treatment options. Multiple Phase 2 studies of VX-135 as part of all-oral treatment regimens are ongoing, including studies of VX-135 in combination with ribavirin in the United States and Europe and a study of VX-135 in combination with daclatasvir, an NS5A replication complex inhibitor, in New Zealand. Dosing of 100 mg and 200 mg of VX-135 is complete in the European study and ongoing in the New Zealand study. Dosing of 100 mg of VX-135 is ongoing in the U.S. study. Under a previously announced partial clinical hold, Vertex will not evaluate a 200 mg dose of VX-135 in the United States without authorization from the FDA. Vertex provided a comprehensive update on the status of these studies in a press release issued July 25, 2013. Autoimmune Diseases Vertex's strategy in autoimmune diseases is to maximize the value of VX-509 across multiple autoimmune diseases globally. The company will evaluate collaborative opportunities that provide funding and capabilities to broaden and accelerate global development of VX-509. Ongoing Phase 2b Study of VX-509 in Rheumatoid Arthritis Enrollment is complete in a 24-week Phase 2b study of VX-509, a selective JAK3 inhibitor, in people with moderate to severe rheumatoid arthritis (RA) receiving methotrexate. The primary endpoints of this study will be measured after 12 weeks of treatment, and data from this study are expected in the second half of 2013.