Bioequivalence and Bioavailability Forum

Add more subjects after a failed BE study of a HVD [Study As­sess­ment]

posted by wxp  – China, 2013-05-28 07:13 (4777 d 09:46 ago) – Posting: # 10668
Views: 16,482

❝ ... Translating statistics into simple words: You have already “consumed” the entire 5% in the first study and nothing is “left” for the add-on.

❝ Some remarks for the future:Always plan for the PK metric with the higher CV (in most cases C_max)...

Thank you, Helmut, for your explanation and answers to my questions. I learnt a lot from the failed BE study. It is worth the time to make a deliberate plan （protocol) before the study.

❝ ... 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.

❝ • Learn from the failed study. Did you sample frequently enough in order to “catch” C_max in all subjects? This is a very important aspect especially for delayed release formulations...

It was a BE study of an old drug's conventional tablet. We sampled frequently enough to "catch" the Cmax.

Thanks a lot for the slides and references.

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 HVDwxp 2013-05-28 05:13
      • Still many subjects… Helmut 2013-05-28 12:56