title: Case studies to test: A framework for using structural, reactivity, metabolic and physicochemical similarity to evaluate the suitability of analogs for SAR-based toxicological assessments.
abstract: A process for evaluating analogs for use in SAR (Structure-Activity Relationship) assessments was previously published (Wu et al. 2010). Subsequently, this process has been updated to include a decision tree for estrogen binding (from US EPA) and flags for developmental and reproductive toxicity (DART). This paper presents the results of blinded case studies designed to test this updated framework. The results of these case studies support the conclusion that the process outlined by Wu et al. (2010) can be successfully applied to develop surrogate values for risk assessment. The read across results generated by the process were shown to be protective when compared to the actual toxicity data. Successful application of the approach requires significant expertise as well as discipline to not overstep the boundaries of the defined analogs and the rating system. The end result of this rigor can be the inability to read across all endpoints for all chemicals resulting in data gaps that cannot be filled using read across, however, this reflects the current state of the science and is preferable to making non-protective decisions. Future work will be targeted towards expanding read across capabilities. Two examples of a broader category approach are also shown.
authors.affiliation: Central Product Safety Department, The Procter and Gamble Company, Miami Valley Innovation Center, 11810 E. Miami River Road, Cincinnati, OH 45040, USA. blackburn.kl@pg.com
authors.forename: Karen
authors.initials: K
authors.lastname: Blackburn
authors.forename: Donald
authors.initials: D
authors.lastname: Bjerke
authors.forename: George
authors.initials: G
authors.lastname: Daston
authors.forename: Susan
authors.initials: S
authors.lastname: Felter
authors.forename: Catherine
authors.initials: C
authors.lastname: Mahony
authors.forename: Jorge
authors.initials: J
authors.lastname: Naciff
authors.forename: Steven
authors.initials: S
authors.lastname: Robison
authors.forename: Shengde
authors.initials: S
authors.lastname: Wu
mesh_terms: D000826:Animal Testing Alternatives; D000818:Animals; D015415:Biomarkers; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012098:Reproduction / Q000187:drug effects; D018570:Risk Assessment / Q000379:methods*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D013329:Structure-Activity Relationship; D018675:Toxicity Tests / Q000379:methods*; D014116:Toxicology / Q000379:methods*; D015262:Xenobiotics / Q000737:chemistry / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D015262:Xenobiotics