sample size re-estimation: controlling the type-1 error regulatory-industry presentation - y...
TRANSCRIPT
YannisJemiai,Ph.D.26September2017
ASABiopharmaceuticalSectionRegulatory-IndustryStatisticsWorkshop
SampleSizeRe-Estimation:ControllingtheType-1Error
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unblinded samplesizere-estimationisanessentialdesigntool
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Addressesuncertaintyintrialdesignassumptions
Oneofthemostpopularadaptations,especiallywhenusingaPromisingZoneapproach
21st CenturyCuresAct,PDUFAVI,encouragetheuseofadaptivedesigns
RegulatoryguidancedocumentsexistfromEMA(2007),FDACDER/CBER(2010),andCDRH(2016)
Increasinglymanyexamplesofregulatoryacceptance
Regulatory-IndustryStatistics
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SowhataresomeoftheissuesconcerninguSSR designs?
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Cantype-1errorbecontrolled?
Cansoundadaptivedecisionrulesbedeveloped?
Howdowegetapointestimateandconfidenceintervalsforthetreatmenteffect?
Howdoweavoidoperationalbiasduringtrialconduct?
Wefocushereontype-1errorcontrol
Regulatory-IndustryStatistics
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Whydoestype-1errorgetinflated?
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Consideratwo-stagedesignwithoutsamplesizeincrease
SupposenowthatweincreasethesamplesizeinstageIIfromn(2) ton*(2),butwedonotchangethecriticalvalue
Thiswillleadtotype-1errorinflation
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Howcanwecontroltype-1errorthen?
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Chronologyofdevelopment(partiallist)
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1.Useaweightedstatisticwithpre-specifiedweights
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Alsocalledthep-valuecombinationapproach
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2.UsetheConventionalWaldStatistic
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ExtendedCDLMethod
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Whydoesitwork?
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… andwhataretheconcerns?
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3.PreserveConditionaltype-1errorrate
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Preservingtheoveralltype-1errorrate
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Conditionaltype-1errorrate
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Conditionaltype-1errorrate
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Conditionaltype-1errorrate
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Conditionaltype-1errorrate
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Conditionaltype-1errorrate
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Pointstoconsider
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Handlingsurvivalendpoints
Usableinformationatinterimanalysis
Non-inferiority&equivalencesettings
Independentincrements
Smallsamples
Regulatory-IndustryStatistics
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Recap:challengesinunblinded SSRtrials
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Type-1errorcontrolisnotanobstacle.Methodsexisttoensurestrongcontrol
Inferenceremainsachallenge,butmakingsomeprogress
Decision-makingalgorithmcanbeoptimizedusingsimulationsandlatestresearch
Operationalbiascanbeaddressed/minimizedbyusingiDMCs,puttinginplaceproperprocesses,andmakinguseoftechnology
Regulatory-IndustryStatistics
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“Byfailingtoprepare,youarepreparingtofail.”
- BenjaminFranklin
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Thankyou
YJemiai– 26Sep2017 Regulatory-IndustryStatistics