Malignant pleural mesothelioma (MPM) is a cancer of the pleura with few treatment options and an infaust prognosis. We developed a short-term primary tumor culture model from tumor cells derived... Show moreMalignant pleural mesothelioma (MPM) is a cancer of the pleura with few treatment options and an infaust prognosis. We developed a short-term primary tumor culture model from tumor cells derived from pleural fluid of MPM patients and performed drug screening on these cultures to guide treatment decisions of corresponding patients. We observed a high concordance between in vitro results and clinical outcomes and defined three subgroups responding differently to the anti-cancer drugs tested. Gene expression profiling yielded distinct signatures that segregated these subgroups and demonstrated that the fibroblast growth factor pathway was most prominently involved. Pharmacogenomic profiling revealed a subgroup of immortalized and primary MPM lines that appeared highly sensitive to FGFR inhibition. BAP1 protein loss was associated with enhanced sensitivity to FGFR inhibition. Gene expression analyses revealed an association between BAP1 loss and increased expression of the receptors FGFR1/3 and ligands FGF9/18. BAP1 loss was associated with activation of MAPK signaling. These associations were confirmed in a cohort of MPM patient samples. Furthermore, 34 patients were treated in a clinical trial with nivolumab which demonstrated meaningful clinical efficacy and a manageable safety profile in pretreated patients with mesothelioma. PD-L1 expression did not predict for response in this population. Show less
