Vertex falls on final VX-809/ Kalydeco data

Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) fell $9.93 (16%) to $51.18 on Thursday after reporting final Phase II data of VX-809 plus Kalydeco ivacaftor to treat cystic fibrosis (CF) patients with one or two copies of the delta F508 CFTR mutation. The most promising results were in the 20 homozygous patients receiving the highest of three VX-809 doses (600 mg once daily). That group showed a significant 6.7% mean absolute improvement in lung function vs. placebo, as measured by FEV1. However, the improvements were less robust than the interim data pooled from all three dose groups announced last month that showed an 8.5% improvement in 37 homozygous patients.

For the first time, the company disclosed data from the study's heterozygous cohort -- Vertex said lung function improvements in heterozygous patients were better than placebo but not as good as in homozygous patients. ...