Pre-clinical research of Myelodysplastic Syndromes (MDS) is hampered by a lack of feasible disease models. Previously, we have established a robust patient-derived xenograft (PDX) model for MDS. Here, we demonstrate for the first time that this model is applicable as a pre-clinical platform to address pending clinical questions by interrogating the efficacy and safety of the thrombopoietin receptor agonist eltrombopag. Our pre-clinical study included n=49 xenografts generated from n=9 MDS patient samples. Substance efficacy was evidenced by FACS-based human platelet quantification, and clonal bone marrow evolution was reconstructed by serial whole exome sequencing of the PDX samples. In contrast to clinical trials in humans, this experimental setup allowed vehicle- and replicate-controlled analyses on a patient-individual level deciphering substance-specific effects from natural disease progression. We found that eltrombopag effectively stimulated thrombopoiesis in MDS PDX without adversely affecting the patients’ clonal composition. In conclusion, our MDS PDX model is a useful ... (Show More)

Pre-clinical research of Myelodysplastic Syndromes (MDS) is hampered by a lack of feasible disease models. Previously, we have established a robust patient-derived xenograft (PDX) model for MDS. Here, we demonstrate for the first time that this model is applicable as a pre-clinical platform to address pending clinical questions by interrogating the efficacy and safety of the thrombopoietin receptor agonist eltrombopag. Our pre-clinical study included n=49 xenografts generated from n=9 MDS patient samples. Substance efficacy was evidenced by FACS-based human platelet quantification, and clonal bone marrow evolution was reconstructed by serial whole exome sequencing of the PDX samples. In contrast to clinical trials in humans, this experimental setup allowed vehicle- and replicate-controlled analyses on a patient-individual level deciphering substance-specific effects from natural disease progression. We found that eltrombopag effectively stimulated thrombopoiesis in MDS PDX without adversely affecting the patients’ clonal composition. In conclusion, our MDS PDX model is a useful tool for testing new therapeutic concepts in MDS preceding clinical trials.

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