Comparison of sweat chloride and FEV1% predicted as phase II endpoints assuming thresholds of effect comparable with those observed for lumacaftor–ivacaftor
| Change in sweat chloride | Change in FEV1% predicted | |
|---|---|---|
| Hypothesised treatment effect (new modulator—placebo) | 10 mmol/L | 3.0% predicted |
| Estimated SD* | 10 | 6.5 |
| Subjects per group† | 16 | 74 |
| Treatment duration | 3–7 days | 14–28 days |
*SD estimates of the 28-day change in sweat chloride and FEV1% predicted derived from prior trials.26
†1:1 randomisation, two-sided t test with 80% power and two-sided 0.05 level of significance.