Bioequivalence and Bioavailability Forum

Dear Helmut
Thank you for your response.

I am talking about sirolimus. This agent have a high intra-subject CV%, but is also subject for TDM.

"The therapeutic window of sirolimus may be relatively narrow. Therefore, optimal use of sirolimus requires careful attention to maintenance of therapeutic levels". (National PBM Drug Monograph Sirolimus (Rapamune^®)).
and
"As described for the solution, the intra- and inter-individual variability in trough levels is high (40-50%)" (see page 17 in the following link http://www.ema.europa.eu/humandocs/PDFs/EPAR/rapamune/420600en6.pdf).

The problem here is that the sponsor requested a bioequivalence study in healthy subjects.
I have seen before different studies performed with other immunosuppressives (cyclosporin) in healthy volunteers, but only 2-way crossover. Any increase number of periods will harm the safety profile.

I don't know what to do now. Too many subjects to be enrolled.
Kindest regards, Jo

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Edit: Document linked. [Helmut]