ANVISA guidelines for two-stage design [Two-Stage / GS Designs]

posted by Mauricio Sampaio  – Brazil, 2020-02-11 21:52 (1560 d 13:30 ago) – Posting: # 21160
Views: 7,442

(edited by Mauricio Sampaio on 2020-02-12 17:16)

Dear, ANVISA has made available a new draft on bioequivalence studies and a chapter on two stage design.

Below are the points.

Please, you could make contributions so that we can be in line with the other guidelines.

Art.75. For two-stage studies, the following should be noted:
  1. It is acceptable to use a two-stage approach to demonstrate bioequivalence based on unknowledgement of the intra-individual variability of the drug;

  2. An initial group of subjects can be treated and their data analyzed;

  3. If power is not sufficient and bioequivalence has not been demonstrated, an additional group can be recruited and the results of both groups will be combined in a final analysis;

  4. This second group must have, at least, 50% of the previous group;:confused:

  5. Type I error must be preserved and adjusted, and in order to demonstrate bioequivalence the level of confidence is 94.12%:confused:;

  6. In the protocol, the stopping criteria must be clearly defined before the study and the analysis of the first step must be treated as an interim analysis; and

  7. When analyzing the combined data from the two stages, the stage variable should be included in the ANOVA model and its influence verified

In my opinion it could be better. So, I would like to hear your opinion.

Thank you in advance!

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