CAMBRIDGE, Mass., Oct 20, 2008 (BUSINESS WIRE) -- Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) today announced positive results from a preliminary analysis of data from Part 2 of the Phase 2a clinical trial of the investigational oral drug VX-770 in cystic fibrosis (CF) patients who carry the G551D CFTR mutation. VX-770, an investigational CFTR potentiator, was well-tolerated when dosed orally as 150 mg or 250 mg twice daily for 28 days. In this analysis, no patients discontinued treatment and no serious adverse events were reported. At both the 150 mg and 250 mg doses, significant improvements in lung function, as measured by an increase in FEV1, and significant improvements in the function of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, as measured by changes from baseline in sweat chloride levels and changes in nasal potential difference (NPD), were observed. In patients receiving placebo, a smaller increase in FEV1 was observed at 28 days that was not statistically significant, and no significant changes from baseline in sweat chloride levels or NPD were observed. Based on these results, Vertex intends to work with global regulatory authorities to finalize the design of a registration program for VX-770 targeted to begin in 2009. VX-770 was developed with support from Cystic Fibrosis Foundation Therapeutics, Inc., the nonprofit affiliate of the Cystic Fibrosis Foundation.

"VX-770 targets the underlying defect in the CFTR protein that causes cystic fibrosis, and represents a potentially new approach to changing the treatment of this disease," said Frank Accurso, M.D., Director of the Cystic Fibrosis Center and Professor of Pediatrics at the University of Colorado School of Medicine in Denver. "In patients with CF, dysfunctional or missing CFTR is believed to result in abnormal balance of fluid and salt in the airways. These data from patients with a particular type of dysfunctional CFTR are consistent with earlier findings obtained in Part 1 of this trial, in which VX-770 was dosed for 14 days, and further support the clinical potential of CFTR modulators such as VX-770."

Robert J. Beall, Ph.D., President and Chief Executive Officer of the Cystic Fibrosis Foundation, said, "Data from the Phase 2 trial of VX-770 provides evidence that a small molecule can address the basic defect in cystic fibrosis and suggests that modulation of CFTR may play an important role in CF therapy. The CF community looks forward to reviewing these data at this week's North American Cystic Fibrosis Conference where the world's leading CF caregivers will see these data in detail for the first time."