Bioequivalence and Bioavailability Forum

Hi mrtin,

» There are two types of covariates (type 1: continous = subject specfic values; and type 2: categorical variable with a few levels).

Type 2 sounds like the very thing that I would call a fixed factor.

» At the first glance a different regulatory pathway might be worth considering based on a PK or exposure similarity evalulation as in such a case there could be more flexibility regarding acceptance of statistical models used to test for equivalence in PK metrics.
»
» Happy to get your thoughts on this idea.

I would always recommend to approach regulators for a discussion. They will always listen but not always agree.

Injectable? Sometimes surface area or body weight is reasonable for exposure modeling. That's a covariate in the word's best sense As in, a continuous variable. If multiple periods or longitudinal study, a covariates like bw may change over time.