Bioequivalence and Bioavailability Forum • Common variance!

Common variance! [Design Issues]

posted by jag009 – NJ, 2012-06-12 21:56 (5117 d 00:16 ago) – Posting: # 8719
Views: 11,107

Hi Helmut,

❝ Thinking it over I would expect that the FDA will not like this approach. What if it’s the other way ’round? Three tests; T1 and T2 perform bad in terms of their PEs whilst T3 is fine. Now let’s assume that s²_WT1=s²_WT2=s²_WR ≪ s²_WT3. The pooled s²_W will be ‘dampened’ by the (later dropped) formulations T1 and T2. In other words you would never be able to demonstrate BE of T1 in a 2-way XOver of the same size. Though theses variances are not accessible in a nonreplicate design I think that the FDA wouldn’t like the idea of approving a product with a potential ‘variance-brake’ in the pivotal study.

Totally agree. Could I hypothetically strip the two treatments (successful test formulation and the reference) and re-run stats in a two-way crossover fashion to re-evaulate the data? Would that stand a chance with regulatory? Just a thought...

Thanks

John

Complete thread:

Curiosity: Running BE studies with more than 2 arms jag009 2012-06-11 15:01 [Design Issues]
- Common variance! Helmut 2012-06-11 16:23
  - Common variance! jag009 2012-06-11 17:25
    - Common variance! Helmut 2012-06-11 17:35
      - Common variance! jag009 2012-06-11 20:03
        
        Common variance! ElMaestro 2012-06-11 20:34
        
        Common variance! Helmut 2012-06-12 01:03
        
        Common variance! ElMaestro 2012-06-12 13:22
  - Common variance!jag009 2012-06-12 19:56
    - What if I run a study with 2 references? jag009 2012-06-12 20:00
    - Common variance! Helmut 2012-06-12 20:39
      - Two References d_labes 2012-06-13 09:11
        
        Two References jag009 2012-09-10 22:48
        
        Two treatments only d_labes 2012-09-11 08:20
  - Common variance! jag009 2012-06-13 16:08