Bioequivalence and Bioavailability Forum

Dear all,

I would be pleased to get your advice on the following. We are planning to conduct a pharmacokinetic with adaptive design (two-stage design). Following the lectures from Helmut and the recommendations from the EMA, we decided to use the method B described by Potvin as the study will be performed in EU country.

However, we have some questions regarding the regulatory procedure that should be followed for such a study. Indeed, the stage I will be submitted following a standard CT application including the number of subjects that will be included in the stage I. But what about the stage II? Do we have to notify the CA/EC with the number of subjects to be included in the stage II according to the results obtained after stage I?
Or can we define in the study protocol a maximum number of subjects that will be allowed to participate in the study (stage I + stage II)?

Furthermore, in this two-stage study, we would like to assess the biovailability of two treatment tests (two different formulations) versus a reference treatment. Could you please advice if it is acceptable to perform a two-stage design study with 3 treatments?

Thanks in advance for your feedback,
Kind regards,