Fig. 1

Identification of optimal therapeutics using PDX mouse clinical trials. PDX models are potentially useful when the optimal course of treatment cannot be readily determined for individual patients. For instance, in the illustration, there are three patients (A-C) with gastric cancer, who hope to receive treatment with the novel therapy drug X if its therapeutic efficacy is proven. In this case, it would be time-consuming and require significant clinical risk to compare the therapeutic response to conventional drugs and the new drug X without “co-clinical trials.” While xenografts derived from patient A respond to drug X, xenografts derived from patient C respond to conventional treatments, but not drug X (step 1). Contrastingly, patient B–derived xenografts partially respond to both therapeutics. This pre-clinical screening by an avatar model is helpful to determine which treatment would have the optimal outcome in each patient (step 2)