Bioequivalence and Bioavailability Forum • Appropriate wording for a protocol

Appropriate wording for a protocol [Two-Stage / GS Designs]

posted by Helmut – Vienna, Austria, 2019-09-09 23:27 – Posting: # 20567
Views: 1,952

Hi ElMaestro,

» » 1. Should we include the information that evaluation after stage 1 completion should be performed assuming GMR=0.95?
»
» I would do so.

So would I.

» » 2. Should we describe the maximum number of subjects who can be included in whole or in stage 2?
»
» I would only put a cap on it if you can refer to simulations having done exactly so (having done so in exactly your way of capping).

From a regulatory perspective this is not necessary. Any futility rule (like max. n₂) decreases the chance to show BE if compared to a published method without one. Hence, if the type I error was controlled in a method without a futility rule, the TIE will always be lower with a futility rule. However, if a futility rule is too strict, you may shoot yourself in the foot since power might be compromised. To check that, sim’s are a good idea indeed.

» » 3. Any other information that should be clearly stated in order to be accurate and to satisfy regulatory authorities?
»
» Exact decision tree, and exact values for alphas, desired power level, and power being calculated using GMR=0.95.

Yep.

» » 4. What if BE criteria are met after stage 1, but estimated power is too low (e.g. 30%)?
»
» It is not a crime to be lucky.

Absolutely. As one of the grumpy old men: Forget power, doesn’t matter.

—
Cheers,
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. ☼
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Complete thread:

Appropriate wording for a protocol Elena777 2019-09-09 19:34 [Two-Stage / GS Designs]
- Appropriate wording for a protocol ElMaestro 2019-09-09 21:39
  - Appropriate wording for a protocol Helmut 2019-09-09 23:27
  - Appropriate wording for a protocol Ohlbe 2019-09-10 10:27
- Which country? Helmut 2019-09-09 23:17
  - Which country? Elena777 2019-09-11 20:24
    - EEU-rules, TSD-methods (lengthy answer) Helmut 2019-09-12 01:31
      - EEU-rules, TSD-methods (lengthy question) Astea 2019-09-14 14:56
        
        n2 based on PK metric with higher CV Helmut 2019-09-16 11:50
        
        Q&A ref Astea 2019-09-16 18:28
        
        The omniscient oracle has spoken Helmut 2019-09-17 12:27
        
        The omniscient oracle has spoken Astea 2019-09-17 20:34
        
        OT: Булга́ков Helmut 2019-09-18 12:12
        
        n2 based on PK metric with higher CV Elena777 2019-09-16 19:48
        
        AUC passes with 0.05 and Cmax with 0.0294 Helmut 2019-09-16 23:30
        
        AUC passes with 0.05 and Cmax with 0.0294 Mikalai 2019-09-18 16:56
        
        Hybrid B/C Helmut 2019-09-18 17:09
        
        AUC passes with 0.05 and Cmax with 0.0294 Elena777 2019-09-19 08:34
        
        Use data of all dosed subjects Helmut 2019-09-19 15:16
        
        Use data of all dosed subjects Elena777 2019-09-19 15:27
        
        ‘Method C’ ⇒ risky Helmut 2019-09-19 16:15
        
        EEU-rules, TSD-methods (lengthy question) Elena777 2019-09-16 19:35
        
        apple tree for two-stage Astea 2019-09-16 20:39
        
        overripe apples Helmut 2019-09-16 23:37
        
        override apples Astea 2019-09-17 06:14