Bioequivalence and Bioavailability Forum

Dear all
anybody familiar with biosimilars? If you have a small peptide (<50 aminoacids) and you can clearly show beside the aminoacid sequence that the chemical structure is exactly the same as in the originator drug do you need really more than a bioequivalence study to proof safety and efficacy?
It is always told that the standard generic approach by demonstration of bioequivalence is in principle not sufficient to demonstrate similarity of biological/biotechnology-derived products due to their complexity. But hold this also true for a small peptide which is not complex like a therapeutic protein (>50 aminoacids)? Guideline CHMP/437/04 Rev 1 states that in specific circumstances, a confirmatory clinical trial may not be necessary. This requires that similar efficacy and safety can clearly be deduced from the similarity of physicochemical characteristics, biological activity/potency, and PK and/or PD profiles of the biosimilar and the reference product.
However this sounds quite vague and I would like to know the prerequisites to follow the simple approach. Where can I find more Information? Of course it is a case by case decision but it would be helpful to know the pitfalls.
Looking forward to your replies.
Kind regards
Dr_Dan