Bioequivalence and Bioavailability Forum

Still many subjects… [Study Assessment]

posted by Helmut – Vienna, Austria, 2013-05-28 14:56 (4367 d 05:28 ago) – Posting: # 10673
Views: 13,410

Hi Xipei,

❝ ❝ ... You would need a replicate design (preferably a full replicate: RTR|TRT or RTRT|TRTR). For the required sample sizes see sampleN.RSABE (FDA) and sampleN.scABEL (EMA).

❝

❝ I tried both with CV=0.68. 42 subjects are needed for EMA, while only 27 subjects are needed for FDA. We plan to redo the BE study with a RSABE or SCABEL design.

Ok, but only if CFDA accepts scaling! I would rather opt for a four period full replicate design (sample sizes for ABEL 30 and for RSABE 20), if

your analytical method can handle small sample volumes (limited by total blood loss) and
you don’t expect too many drop-outs (more likely in four periods).

The partial replicate is statistically tricky. Another option would be a full replicate three period design (RTR|TRT), but it is not implemented in PowerTOST yet (though I expect similar sample size like in the partial replicate) and you have to adapt FDA’s and EMA’s code (easy).

If CFDA does not accept scaling and 75–133% is applicable for C_max (your other post) you would need (T/R 0.95, CV 0.68, 80% power):

design       PowerTOST  n   treatments    power

RT|TR          2×2      92     184      0.805498

RRT|RTR|TRR    2×3×3    69     207      0.807633

RTR|TRT        2×2×3    68     204      0.801400

RTRT|TRTR      2×2×4    46     184      0.807602

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Helmut Schütz

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Complete thread:

Add more subjects after a failed BE study of a HVD wxp 2013-05-27 10:34
- bad luck Dr_Dan 2013-05-27 12:28
  - bad luck wxp 2013-05-27 14:19
- Beware of Add-on Studies! Helmut 2013-05-27 13:51
  - Beware of Add-on Studies! Shuanghe 2013-05-27 15:59
    - Oh wow! Helmut 2013-05-27 16:21
      - The same criterion of Cmax in China now wxp 2013-05-28 06:10
        
        SFDA ⇒ CFDA Helmut 2013-05-28 13:02
        
        Helmut, updated Chinese BE guideline here Shuanghe 2013-06-14 11:05
        
        BE in Chinese Pharmacopoeia Helmut 2013-06-14 14:22
        
        BE in Chinese Pharmacopoeia Shuanghe 2013-06-14 14:56
        
        BE in Chinese Pharmacopoeia Helmut 2013-06-14 16:11
  - Add more subjects after a failed BE study of a HVD wxp 2013-05-28 05:13
    - Still many subjects…Helmut 2013-05-28 12:56

Still many subjects… [Study As­sess­ment]

Complete thread:

Still many subjects… [Study Assessment]