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SUMMARY:BSU Seminar: &quot\;Design and Inference for Enrichment Trials wit
 h a Continuous Biomarker&quot\; - Prof William Rosenberger\, George Mason 
 University
DTSTART:20220705T130000Z
DTEND:20220705T140000Z
UID:TALK175997@talks.cam.ac.uk
CONTACT:Alison Quenault
DESCRIPTION:Joint work with Nancy Flournoy\, Rosamarie Frieri\, and Zhanta
 o Lin \n\nWe describe the philosophical approaches to two-stage enrichment
  designs\, in which a benefitting subpopulation is targeted in a second st
 age\, after a first stage identifies the threshold of a predictive\, conti
 nuous biomarker. The design issue we address is sample size estimation for
  the first and second stages\, and the consequences of poorly estimating t
 he threshold. These design issues are established based on an approach whe
 re the two stages are conducted and analyzed separately\, and stage two is
  considered a confirmatory trial. Another approach is to combine the data 
 from the two stages\, and we demonstrate how to do that by testing two hyp
 otheses simultaneously with test statistics that (we show) have an asympto
 tic normal distribution. While a bivariate normal model is used to give in
 sights into the predictive nature of the biomarker\, and to visualize some
  closed-form solutions\, in principle other models can certainly be used (
 but perhaps yield fewer insights). As in many ongoing\, long-term research
  projects\, our work probably raises more questions than it answers!\n
LOCATION:Seminar Room 12\, School of Clinical Medicine\, Hills Rd\, Cambri
 dge CB2 0SP
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