Re: Interpreting ABBV/ENTA’s SAPHIRE-1 results
98% SVR12 in GT1b and 95% SVR12 in GT1a—both on an ITT basis—are excellent efficacy results, of course. However, SAPHIRE-1 (and the yet-to-report SAPHIRE-2) are primarily safety studies, as noted in #msg-91739317.
How did the 3-DAA+ribavirin arm perform in SAPHIRE-1 relative to the placebo arm onsafety? From today’s PR:
The most commonly reported adverse events in the 3D and placebo arms, respectively, were fatigue, headache and nausea. Discontinuations due to adverse events were reported in 0.6 percent of patients receiving the 3D regimen and0.6 percent of patients receiving placebo.
In other words, there were no excess dropouts in the treatment arm relative to the placebo arm, which is as good an outcome as one could hope for (pending the detaileddata on AEs to be presented at a medical conference).
All told, SAPHIRE-1 looks like an excellent start to ABBV/ENTA’s array of six phase-3 trials for the initial NDA submission in 2Q14. The five other phase-3 trials to support the initial NDA are SAPHIRE-2, PEARL-2/3/4, and TURQUOISE-2, as detailed in #msg-93647264.
Background on SAPHIRE-1: The “placebo” arm in SAPHIRE-1 was actually a delayed treatment arm insofar as patients received the same regimen as the treatment arm, but the start of treatment was delayed by 12 weeks in order to make a safety comparison between the arms. HCV progresses much too slowly for a 12-week delay to affect the efficacy results in the delayed-treatment arm (which have yet to be reported).