J. Liu,1 B. Corrigan,2 T. Nicholas,2 K. Ito,2 L. Zhao,3 D. A. Flockhart1; 1Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 2Global Clinical Pharmacology, Global Innovative Pharma at Pfizer Inc., Groton, CT, 3Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD

BACKGROUND: “Shiny," a free R package for developing interactive web apps, has been applied to visualize, summarize and communicate data. Few or no "Shiny" apps have been developed for modeling visualization. A browser based app was created using “Shiny” and “metafor” to allow interactive web based pharmacometric modeling of literature based data.
METHODS: Package “metafor” was used to allow reactive interaction between modeling parameter inputs and result outputs. MARS was placed on an external R server allowing public access: https://jzliu.shinyapps.io/MARS/.<br />RESULTS: Figure. 1 shows the user interface developed using two R scripts. Data can be uploaded via the webpage. After selecting parameters and variables, the “measure” and its variance can be calculated or downloaded. In the “Fitting Model” tab, the model summary and diagnostic plots can be obtained with or without moderator. Specific plots are available to view or download in the “Diagnostic Plots” tab. In addition, functions of nested models comparison, cumulative analysis, deletion diagnostics and values prediction, were combined in the “More” tab.
CONCLUSION: MARS is the first example for “Shiny”-based interactive web app that performs pharmacometric modeling, which offers a free, effective and reusable way for sharing modeling results with both R and non-R users.