All Times EDT
Keywords: FDA guidance, animal studies, veterinary, innovative designs
This talk will provide regulatory background and summarize the main recommendations of the four guidance for industry (GFIs) published in 2021 that describe pathways for animal drug sponsors to use adaptive study designs, real world evidence and biomarkers, or leverage data collected from foreign studies to establish drug effectiveness to support approval of their products. The presentation will highlight key statistical principles that should be considered in the design, analysis and interpretation of animal drug regulatory studies that utilize these innovative approaches.
Animal drug evaluation has unique challenges in the use of innovative approaches, due in part to small study sizes, difficulties in assessing animal response, and inherent variability of target populations. For example, the approaches described in GFI 268 “Adaptive and other Innovative Designs for Effectiveness Studies of New Animal Drugs” could use existing designs and methods developed for human clinical trials (e.g., to control Type 1 error for sample size re-estimation or for group sequential designs). However, direct applicability to veterinary studies is not assured because of differences in design and endpoints evaluated. Specifically, many of the existing methods are for normally distributed outcomes, and the statistical model does not include random effects; in contrast, most animal regulatory field studies have binomial outcomes, and employ mixed models. Work is needed to confirm methods that are directly applicable, and to identify and make the needed adjustments to existing methods. Possible areas of research that can address this and other open questions will be explored, with particular focus on issues where CVM, industry, and academia can work collaboratively to support the utilization of the pathways recommended in each GFI.