Vertex Pharmaceuticals Phase 3 Study of VX-770 in Children Ages 6 to 11 With a Specific Type of Cystic Fibrosis Showed Profound Improvements in Lung Function and Other Measures of Disease

Vertex Pharmaceuticals Incorporated VRTX today announced positive results from a 24-week analysis of the ongoing Phase 3 ENVISION study of VX-770, an oral medicine in development that targets the defective protein that causes cystic fibrosis (CF). ENVISION (n=52) was designed to evaluate VX-770 among children ages 6 to 11 with the G551D mutation in the CFTR gene. Approximately 4 percent of people with CF in the United States have at least one copy of the G551D mutation. The study met its primary endpoint of mean absolute change from baseline in percent predicted FEV1 (forced expiratory volume in one second, or lung function) through week 24. A difference in mean absolute improvement from baseline in lung function of 12.5 percent and a difference in mean relative improvement from baseline in lung function of 17.4 percent compared to placebo (p<0.0001) were observed through week 24. Significant improvements in other measures of disease, including weight gain and a reduction in sweat chloride, were also observed through week 24 among those who received VX-770. At the time of this analysis, the most commonly reported adverse events were respiratory in nature and comparable across treatment groups. The study is ongoing, and additional assessments of key endpoints will be conducted at the end of the 48-week study.