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ElMaestro ★★★ Denmark, 2015-03-03 19:02 (3722 d 13:50 ago) Posting: # 14537 Views: 7,169 |
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Hi all, I wonder when and how you experts use pilot trials? If you have a candidate formulation and you have no clue if you are anywhere close to a match versus the reference -for example when it is a non-trivial formulation- would you then do a pilot trial? And if yes, how would you use the info derived from it?? E.g. your pilot trial on N=12 says the GMR estimate is 92.6 with a CI from 78% to 110%. Would you assume GMR=95% or would you assume 92.6% or something even worse when planning the pivotal? This paper was just published and discusses such use of pilot trials. As far as I have understood (  ) the author, who is known to be a fellow of rather dubious qualities, argues that when there is genuine uncertainty about the match (which is to say the true GMR) then a pilot trial is perhaps not of much use. This is because using the GMR for the planning of a pivotal trial isn't necessarily a great idea according to the numbers. Pilots appear to be excellent when the uncertainty is on the variability, but then 2stage approaches may be smarter still. Do you have any idea how to use a pilot trial to address a potential lack of match  ?Mucho complicado in my opinion and yet the question is so incredibly simple. — Pass or fail! ElMaestro |
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Dr_Dan ★★ Germany, 2015-03-04 10:26 (3721 d 22:26 ago) @ ElMaestro Posting: # 14547 Views: 5,721 |
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Hi ElMaestro Honestly, I am no friend of pilot studies and of two stage designs either. IMHO a pilot study makes sense if you 1. use a complete different formulation (the situation you described = proof-of-concept) 2. have an alternative (three period design) or know how to reformulate (IVIVC) 3. can not find any PK data in literature. ❝ E.g. your pilot trial on N=12 says the GMR estimate is 92.6 with a CI from 78% to 110%. Would you assume GMR=95% or would you assume 92.6% or something even worse when planning the pivotal? Kind regards Dr_Dan — Kind regards and have a nice day Dr_Dan |
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jag009 ★★★ NJ, 2015-03-04 18:14 (3721 d 14:38 ago) @ ElMaestro Posting: # 14550 Views: 5,631 |
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Hi Maestro, Heheh, welcome to the crazy strategies of first-to-file generics. Some companies would make multiple formulations based on patents and run them again the marketed product right after it becomes available in hope that one of the tests will be a promising candidate... Yes I have a friend who ran bioanalytical 8 days after the RLD was available in the market. ❝ E.g. your pilot trial on N=12 says the GMR estimate is 92.6 with a CI from 78% to 110%. Would you assume GMR=95% or would you assume 92.6% or something even worse when planning the pivotal? I would assume GMR of ~90 and power of 85%-90% based on the CV from the pilot, assuming the CV is far away from 30. I would not go below ~90 but then it's up to senior management who pushes my button :P John |
Ing. Helmut Schütz