Bernard J. Escudier, MD

The article by Posadas and Figlin on systemic therapy in advanced renal cell carcinoma (RCC) provides a very interesting and comprehensive review of our current knowledge concerning the treatment of RCC.

Renal cell carcinoma (RCC) has been considered one of the most difficult tumors to treat for about 20 years. Chemotherapy and radiotherapy have almost no efficacy in this tumor, and cytokines (interleukin [IL]-2 [Proleukin] and interferon) have remained the only available treatment for about 20 years, with a small proportion of patients benefiting from these treatments.

Paralleling the increasing use of multikinase inhibitors in the field of cancer therapy, patients and clinicians are confronted with frequently occurring cutaneous side effects associated with the use of these new drugs. Two such targeted agents, sunitinib (Sutent) and sorafenib (Nexavar), were recently approved by the US Food and Drug Administration to treat patients with metastatic renal cell cancer (RCC).

Several novel targeted agents are being tested for the treatment of advanced renal cell carcinoma (RCC), and results of phase I and II trials have been encouraging. A recently completed phase III, placebo-controlled study showed that median progression-free survival doubled from 12 weeks to 24 weeks in patients treated with the multi-kinase inhibitor sorafenib (Nexavar) (hazard ratio [HR], 0.44; P < .00001), and approximately three-quarters of patients had some degree of tumor regression. Furthermore, interim analysis showed an estimated 39% improvement in overall survival in sorafenib-treated patients (HR, 0.72; P = .018) and an investigator-assessed response rate of 10%, indicating that many more patients had clinical benefit than had tumor regression qualifying as response by traditional criteria. These data and others have added to the evidence of lack of correlation between response rate and clinical benefit in RCC patients (as well as in other tumor types) treated with targeted therapies. Issues surrounding study endpoints and biologic efficacy markers for molecular targeted agents in RCC are discussed in this article, with a focus on results of the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGETs).