Sample Size "Effi­ci­ency" of Replicate CO vs. 2-way CO for NTID [Power / Sample Size]

posted by Sereng  – USA, 2022-01-31 00:11 (610 d 17:17 ago) – Posting: # 22761
Views: 1,714

Dear colleagues, I am struggling with understanding the sample size “benefits” of a replicate study design for NTID. Specifically, for levothyroxine (T4), FDA states that the RSABE approach is to properly adjust the BE criteria based on reference variability and comparing T and R product within-subject variability. The T4, the OGD PSG (cross-referenced to the Warfarin PSG) states that the study must be replicate (2x2x4) and BE established using Cmax and AUC if: (1) Upper 95% CI is ≤0 using RSABE; (2) The 90% CI is within 80-125% (ABE); and (3) The upper limit of the 90% equal-tails CI of the within subject SD of T to R is less than 2.5

What are the sample size “benefits” or “efficiencies” of undertaking this study as a replicate CO design (e.g., Test 50 x 2; Ref 50 x 2) versus a 2-way CO (Test 100 x 2; Ref 100 x 2). Any help would be much appreciated. Many thanks!

Complete thread:

UA Flag
 Admin contact
22,768 posts in 4,777 threads, 1,627 registered users;
16 visitors (1 registered, 15 guests [including 7 identified bots]).
Forum time: 18:28 CEST (Europe/Vienna)

The real struggle is not between the right and the left
but between the party of the thoughtful
and the party of the jerks.    Jimmy Wales

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz