Bioequivalence and Bioavailability Forum

Hi Mittyri,

❝ Does it mean that with a probability 90% the real GMR of Cmax lies between 0.847 and 1.134?

Yes.

❝ Does it mean that the mentioned probability normally distributed in this interval?

No. These are backtransformed values. They are normal distributed with a mean of ln(0.98) = -0.0202 and 90% limits of ln(0.847, 1.134) = -0.1661, +0.1258. These limits are symmetrical around ln(PE): (-0.1661+0.1258)/2 = -0.0202.

❝ Which GMR would you propose? 0.98% (optimistic from previous study)? 0.95% (standard)?

First of all I agree with what ElMaestro wrote. As you know I’m not a friend of post hoc power, but in the previous study with 61% you were lucky to show BE. You are dealing with a HVD / HVDP (CV 38%). For these drugs the PE “jumps around” between studies. Therefore, the two Lászlós recommended in their paper about sample size estimation a conservative T/R of 0.90 – even if you have ob­served a “better” one in a previous study.