Phase 2a of the 809/770 trial showed the limited reduction in sodium chloride levels, etc- that is the press result that resulted in vertex stock dropping, if people remember due to results not meeting expectations. Phase 2b (the phase wrapping up now) involved a longer period on the meds and in larger doses to see if a better result would be obtained, enough to result in significant clinical results ...improved pulmonary function, reduced sweat tests, etc. Problems have been encountered with 809 and 770 interacting- this is known, not conjecture- whether they can overcome this I have no idea.
The major problem with waiting for this phase of 661 to decide which drug to move forward with would be that it has JUST started and is not estimated to be finished until August 2013, so hopefully they will be going by other data in making their decision.
The major problem with waiting for this phase of 661 to decide which drug to move forward with would be that it has JUST started and is not estimated to be finished until August 2013, so hopefully they will be going by other data in making their decision.