RE: Plcebo Corrected PK/PD

From: "Gobburu, Jogarao V" GOBBURUJ@cder.fda.gov Subject: RE: [NMusers] Plcebo Corrected PK/PD Date: Fri, March 4, 2005 11:38 am Dear Nick, Thanks for your note. I wrote 'cannot estimate the true variability in the drug effect", "true" being the qualifier. Yes, models with appropriate assumptions can be used and are being used to estimate the variability in the drug effect. However, unless we really know how each patient behaves on both placebo and drug (cross-over), we do not have the right data to estimate the bsv and wsv of the drug effects. Our reference for placebo effect, otherwise, would be a typical patient and not that particular patient (in my parallel design example). This ignores the bsv of placebo effect while determining the drug effect in each patient. I thought it is important to note that. Sure, those models will still be useful. Regards, Joga