Bioequivalence and Bioavailability Forum • is something fishy in case 2?

is something fishy in case 2? [Regulatives / Guidelines]

posted by ElMaestro – Denmark, 2008-11-29 16:42 (6422 d 16:51 ago) – Posting: # 2835
Views: 9,106

Dea Dr Garg,

I am not sure I follow you completely regarding case 2:

❝ Case-2: I have done another pilot study with parallel design for a very long half-life drug B and I have calculated the sample size for the pivotal study using SAS considering total CV of 0.16 and observed %T/R ratio of 112.08. The sample size calculated is 27 for two-way cross-over study as programmed. In that case can I do the pivotal parallel study with at least double the number of subjects i.e. 54?

Not considering the last sentence there, I get the impression that you first did a parallel pilot which gave you a CV and a T/R estimate, which you then used to power a crossover trial?
This does not sound right. As indicated in previous question and further elaborated on by DLabes, the CV you get in a parallel study is not the intra-CV you need for powering the crossover trial.
As a rule of thumb a parallel pilot study will give you info you can use to plan another parallel study; a crossover pilot will give you what you need to power another crossover trial (or optionally even a parallel one).

Best regards
EM.

Complete thread:

sample size for BA/BE studies drmuneesh 2008-10-18 09:17
- sample size for BA/BE studies shankar 2008-10-18 11:47
  - sample size for BA/BE studies drmuneesh 2008-10-18 12:18
    - sample size for BA/BE studies Ohlbe 2008-10-18 13:32
      - sample size for BA/BE studies drmuneesh 2008-10-19 10:42
      - sample size for BA/BE studies drmuneesh 2008-11-17 14:10
        
        sample size for BA/BE studies ElMaestro 2008-11-17 14:32
        
        sample size for BA/BE studies drmuneesh 2008-11-18 10:34
        sample size for BA/BE studies drmuneesh 2008-11-28 07:50
        
        sample size for BA/BE studies Helmut 2008-11-17 15:47
        
        sample size for BA/BE studies drmuneesh 2008-11-18 07:44
        
        sample size for BA/BE studies ElMaestro 2008-11-18 08:49
        
        sample size for BA/BE studies drmuneesh 2008-11-18 09:31
        
        sample size for BA/BE studies ElMaestro 2008-11-18 09:59
        
        sample size for BA/BE studies drmuneesh 2008-11-18 10:27
        
        sample size for BA/BE studies drmuneesh 2008-11-19 10:14
        
        sample size for BA/BE studies ElMaestro 2008-11-19 10:48
        
        sample size for BA/BE studies drmuneesh 2008-11-20 08:30
        
        CVintra # CVinter # CVtotal Helmut 2008-11-20 11:18
        
        Circulus vitiosus d_labes 2008-11-20 13:57
        
        Sterne! Helmut 2008-11-20 18:11
        
        CVintra # CVinter # CVtotal drmuneesh 2008-11-28 10:37
        
        CVintra # CVinter # CVtotal Helmut 2008-11-29 10:14
        
        CVintra # CVinter # CVtotal drmuneesh 2008-11-30 07:18
        
        is something fishy in case 2?ElMaestro 2008-11-29 15:42
        
        is something fishy in case 2? drmuneesh 2008-11-30 07:17
        
        SAS and sample size d_labes 2008-11-19 11:33
        
        SAS and sample size drmuneesh 2008-11-20 08:31