"...Some mutations result in CFTR proteins at the cell surface that do not function properly. They function like a locked door. VX-770 unlocks the door and allows these proteins to function correctly, improving the flow of salt and fluids in and out of the cell.VX-770 is designed to increase the function of the defective protein at the cell surface in people with the G551D mutation. The defective protein functions like a locked door.
VX-770 helps unlock the door at the cell surface, enabling chloride to pass through, as it would in healthy cells. This restores a proper flow of salt and fluids on the surface of the lung. For these reasons, people carrying the G551D mutation appear to have a strong potential to benefit from VX-770.
It is possible that the results of the Phase 3 trials will provide a basis for the use of VX-770 to treat other similar mutations...."So that gives me some hope (okay, a lot of hope) that this new drug, which will hopefully be made available in 2012, will remove the symptoms of CF in Drew and for everyone with Class 3 mutations and not just those with the G551D mutation. And if it doesn't, there is another drug that targets delta F508 that should be available in the next few years. I also found this posted on a CF Forum website: "The thing that gives me the most hope for Class III mutations is this quote from an abstract of a presentation made by Vertex, where they tested VX-770 in-vitro (in a test-tube): Class III mutations