Bioequivalence and Bioavailability Forum

Hi balakotu,

❝ We are planning to conduct one "Replicate 4-period" bio-equivalence study with 70 subjects.

❝ After completion of clinical phase we will analyze only 40 subjects.

❝ If 40 subject’s data is shown bio-equivalent then we will stop the analysis of remaining 30 subjects. If the data is predictable then we will analyze remaining 30 subjects.

This sounds like a two-stage approach. If you allow yourself two chances of showing BE at the usual alpha of 5% then some regulators may protest due to overall type I error inflation. Check publications by Diane Potvin and coworkers for ways forward which retain control of the error.
In addition, I think you should use all available data: If you have data from 70 subjects, then I believe all 70 subjects should be analysed to avoid ethics issues.

"Replicate 4-period" in connection to two-stage designs is so far uncharted territory. I don't recommend trotting down that avenue.