title: Improved up-and-down designs for phase I trials.
abstract: We consider several designs from the family of up-and-down rules for the sequential allocation of dose levels to subjects in a dose-response study. We show that an up-and-down design can be improved by using more information than the most recent response. For example, the k-in-a-row rule uses up to the k most recent responses. We introduce a new design, the Narayana rule, which uses a local estimate of the probability of toxicity calculated from all previous responses. For the Narayana rule, as the sample size gets large, the probability of assignment goes to zero for dose levels not among the two (or three) closest to the target. Different estimators of the target dose are compared. We find that the isotonic regression estimator is superior to other estimators for small to moderate sample sizes.
authors.affiliation: Department of Biostatistics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7420, USA. aivanova@bios.unc.edu
authors.forename: Anastasia
authors.initials: A
authors.lastname: Ivanova
authors.forename: Aliakbar
authors.initials: A
authors.lastname: Montazer-Haghighi
authors.forename: Sri Gopal
authors.initials: SG
authors.lastname: Mohanty
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Durham
mesh_terms: D017321:Clinical Trials, Phase I as Topic / Q000379:methods*; D003198:Computer Simulation; D004305:Dose-Response Relationship, Drug; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage; D012107:Research Design
chemical_list: D004364:Pharmaceutical Preparations