N calculation for trial about PK superiority [Power / Sample Size]

posted by alejandro_jo1990 – Spain, 2022-09-01 16:40 (93 d 21:39 ago) – Posting: # 23252
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Hello to all! first thanks for this wonderful forum, here a young MD, clinical pharmacologist recently moving from clinical trials conduct to design, tryinto apply my (modest) knowledge of clinical PK and biostatistics to phase I trial design. I was discussing with a former colleague. If we were to design a trial to try to support a change in SmPC for a certain product, ie. a faster absorption:

- If we were to demostrate in overall a faster absorption, we would need to design a superiority trial and calculate N based on expected diff in logCmax using logsd (difference or more conservative the higer Cmax maybe?). Suggested log to use a diff in means to calculate N and Cmax as is the parameter to include both extentand and rate of absorption (I deem Tmax as useless).

-If we were to demonstrate a faster absorption at X point (10 minutes), before Tmax, shall I need to use the differences in logAUC with same SD assessment? or concentration at 10 minutes would suffice (or maybe any approach is not correct at all).

I assume I would calculate N based on the difference in means as in any study.

PS. I swear I conducted an intensive research through the forum

BR
Alex

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