Fig. 1. PDO-based individualized tumour response testing as a predictive biomarker.

a Illustrates the tumour types for which patient-derived organoids (PDOs) have been tested for clinical validity (listed in full in Table 1). Personalized treatment strategies currently implemented in oncology treatment largely comprise of genomic biomarkers. However, this only results in a personalized treatment strategy for a minority of patients. Individualized tumour response testing using PDOs is a new biomarker which may be used in personalized treatment and increases access to personalized treatment. b For individualized tumour response testing, tissue from a patient’s tumour is obtained to culture organoids, perform drug screens and various read-outs can be obtained to define PDO drug screen response (including organoid size, viability and co-culture cytokine measurements). A predictive biomarker test is developed using the PDO drug screen results and clinical response seen in patients.