Clinical Trial Participants With Metastatic Renal Cell Carcinoma Differ From Patients Treated in Real-World Practice.

PURPOSE Although narrow eligibility criteria improve the internal validity of clinical trials, they may result in differences between study populations and real-world patients, threatening generalizability. Therefore, we evaluated whether patients treated for metastatic renal cell cancer (mRCC) in routine clinical practice are similar to those enrolled onto clinical trials. PATIENTS AND METHODS In this cohort study, we compared baseline characteristics of patients with mRCC in phase III clinical trials of new targeted therapies and those in a retrospective registry composed of academic (Duke) and community (ACORN Network) practices. RESULTS A total of 438 registry patients received sunitinib, sorafenib, temsirolimus, or pazopanib (most commonly used agents) in first-line treatment. Registry patients receiving tyrosine kinase inhibitors (sunitinib, sorafenib, or pazopanib) were more likely to have poor-risk disease by Memorial Sloan Kettering Cancer Center criteria (poor, 7.4% v 2.9%; P < .001; favorable, 30.1% v 43.8%; P < .001) and to have impaired performance status (Eastern Cooperative Oncology Group > 1, 11.1% v 0.6%; P < .001). However, registry patients receiving temsirolimus were less likely to have poor-risk disease (poor, 10.2% v 69.4%; P < .001; favorable, 16.9% v 0%; P < .001). Thus, 39.0% of registry patients would have been excluded from the phase III clinical trial testing the drug they received. CONCLUSION Patients with mRCC treated with tyrosine kinase inhibitors in real-world clinical practice are sicker than those enrolled onto pivotal clinical trials, and more than one third are trial ineligible. Application of clinical trial findings to dissimilar populations may result in patient harm. Clinical research with more inclusive eligibility criteria is needed to appropriately guide real-world practice.