Animal to human translation: a systematic scoping review of reported concordance rates

BACKGROUND: Drug development is currently hampered by high attrition rates; many developed treatments fail during clinical testing. Part of the attrition may be due to low animal-to-human translational success rates; so-called "translational failure". As far as we know, no systematic overview of published translational success rates exists. SYSTEMATIC SCOPING REVIEW: ) and meta-analyses (percentage overlap of 95% confidence intervals). Translational success rates ranged from 0 to 100%. CONCLUSION: The wide range of translational success rates observed in our study might indicate that translational success is unpredictable; i.e. it might be unclear upfront if the results of primary animal studies will contribute to translational knowledge. However, the risk of bias of the included studies was high, and much of the included evidence is old, while newer models have become available. Therefore, the reliability of the cumulative evidence from current papers on this topic is insufficient. Further in-depth "umbrella"-studies of translational success rates are still warranted. These are needed to evaluate the probabilistic evidence for predictivity of animal studies for the human situation more reliably, and to determine which factors affect this process.