Together, these pharmacokinetic and safety data support inclusion of VX-809 400mg (q12h) in combination with ivacaftor 250mg (q12h) in the Phase 3 program to evaluate the effect that higher exposures of VX-809 have on efficacy and safety.
The pattern of lung function response observed in Cohort 3 was similar to that observed in the 600mg QD dose group in Cohort 2, with a decline in FEV 1 during the VX-809 monotherapy dosing period followed by a statistically significant increase in FEV 1 during the VX-809 and ivacaftor combination dosing period. The within-group mean absolute improvement in FEV 1 observed during the combination-dosing period in Cohort 3 was 6.6 percentage points, compared to 6.1 percentage points for the 600mg QD dose group in Cohort 2.
Additional lung function results for Cohort 3 are provided below:
|Mean Absolute and Relative Changes in Percent Predicted FEV 1||Day 0 – 28; VX-809 Alone||Day 28 – 56; VX-809 + ivacaftor||Day 0 - 56|
|VX-809 (400mg q12h) + ivacaftor (250mg q12h)||
Study in People with One Copy of the F508del MutationIn addition to the Phase 3 studies in people with two copies of the F508del mutation, Vertex plans to conduct an 8-week exploratory Phase 2 study of VX-809 in combination with ivacaftor in people 12 and older with one copy (heterozygous) of the F508del mutation on one allele and a second mutation that is not expected to respond to either ivacaftor or VX-809 alone. This study is designed to provide additional safety and lung function data on the combination in heterozygous patients, and will evaluate the twice daily (q12h) combination of VX-809 (400mg) and ivacaftor (250mg). VX-809 and ivacaftor were discovered as part of a collaboration with Cystic Fibrosis Foundation Therapeutics, Inc., the non-profit drug discovery and development affiliate of the Cystic Fibrosis Foundation.