I have now had a good look at these links and if I am understanding them correctly then I think I need to set the record straight.
The decision support tool shows, for a person genotype 1b, F0-F1, failed protease inhibitor+ifn+riba, that led+sof for 12 weeks = 98% SVR. It does not recommend 24 weeks for the led+sof combo. This is consistent with the Gilead trials for people who are tx experienced with a protease inhibitor.
*** In other words, my suspicions that Gilead fudged the duration of the led+sof combo have been unfounded, according to these recommendations. ***
For the dac+sof combo it is another matter. dac+sof does get a duration of 24 weeks with a 90% SVR outcome, obviously inferior to the led+sof combo for this cohort of people (protease experienced).
So that is a somewhat surprising find for me but hey, who am I to argue with it. Obviously somebody somewhere has formulated these recommendations for a reason. It would be interesting to know those reasons. One presumes that there were trials done on the dac+sof combo. The only trials I know about were the phase 2 trials done before Gilead rejected the BMS dac and decided to go with their own NS5A, ie. led. True enough, I believe that those trials were done for 24 weeks. The progress of dac has always been hindered by the lack of trial data after the split with BMS (except for geno3).
Anyway I am happy to get some clarity on this.