Prediction of response to kinase inhibitors based on protein phosphorylation profiles in tumor tissue from advanced renal cell cancer patients.

The rapid development of agents blocking kinases has established the use of molecularly targeted therapy as the preferred treatment approach for patients with metastatic renal cell cancer (RCC). Five kinase inhibitors (sunitinib, everolimus, temsirolimus, sorafenib and pazopanib) are now approved for clinical use. Response rates differ among these agents, importantly depending on line of treatment. In first-line treatment sunitinib results in 47% objective response rates, where in second-line after cytokines 34% responds. Thus far, it is unclear which patient with advanced renal cell cancer will respond to targeted therapy. In order to select patients for targeted therapies, several profiling approaches have been explored but to date no adequate and reliable test is available. It is assumed that responses to targeted agents depend on specific receptor and protein signalling activities in tumor tissues. Therefore, we propose that protein phosphorylation profiling with phosphoproteomics may be a potential clinical diagnostic tool to predict for tumor response to targeted therapy.

The rapid development of agents blocking kinases has established the use of molecularly targeted therapy as the preferred treatment approach for patients with metastatic renal cell cancer (RCC). Five kinase inhibitors (sunitinib, everolimus, temsirolimus, sorafenib and pazopanib) are now approved for clinical use. Response rates differ among these agents, importantly depending on line of treatment. In first-line treatment sunitinib results in 47% objective response rates, where in second-line after cytokines 34% responds. Thus far, it is unclear which patient with advanced renal cell cancer will respond to targeterd therapy. In order to select patients for targeted therapies, several profiling approaches have been explored but to date no adequate and reliable test is available. It is assumed that responses to targeted agents depend on specific receptor and protein signalling activities in tumor tissues. Therefore, we propose that protein phosphorylation profiling with phosphoprotemics may be a potential clinical diagnostic tool to predict for tumor response to targeted therapy. This approach is expected to increase efficacy, reduce costs an d prevent toxicities from (ineffective) targeted agents.

A feasability analysis will be performed when 20 patients are included.

In this study, a fresh tumor biopsy from a metastasis or a primary tumor will be taken. In all subjects subsequent standard treatment will be initiated according to current clinical guidelines. In addition to this biopsy, collection of urine and blood is performed upon inclusion and the same procedure is optional on 2 other time points during treatment.