Sample size

From prh@pharmacy.wisc.edu Tue Jun 17 19:56:59 1997 Subject: Sample size I am beginning preliminary work to use NONMEM4 to estimate the population PK of two cytotoxics in a cooperative grooup Phase III trial. I would like to use just two samples from each patient, similar to what Dr. Bruno et al reported in their Phase I and II work with docetaxel. Can the group point me in a direction to learn: 1. How should the sampling times be defined and distributed based upon prior known PK parameters for the drug? Should random times be selected (on one extreme) or points suggested by an algortihm such as ADAPT's Sample? 2. How does one define the necessary sample size for a limited sampling study? The clinical study will retrospectively attempt to test the association between PK and response or survival duration. Response would be tested with logistic regression, along with other non-PK parameters if they contribute. I am unsure about the optimal process for the more continuous variable of survival or response duration. I appreciate any guidance that the group can provide. Thanks Paul Hutson, Pharm.D. Associate Professor (CHS) UW School of Pharmacy (608) 263-2496 FAX 265-5421