Promising systemic therapy for renal cell carcinoma.

In the United States, advanced kidney cancer accounts for over 12,000 deaths each year. Immunotherapy with either interferon or interleukin-2 (IL-2) has been the standard of care for over two decades. High-dose IL-2 can apparently cure 10% to 15% of patients treated, but due to the required inpatient care and the attendant toxicities, it is only administered to less than 1,000 patients per year in the United States (Chiron, personal communication). Interferon is a less active agent than IL-2 but it has still been shown to be superior to therapy with either megesterol or vinblastine. Interferon typically results in very few long-term responses and is given to most patients with metastatic kidney cancer. Median survival after interferon therapy is dependent on risk group but is typically 12 to 15 months. Thus, new therapies are urgently needed in this refractory disease. Novel compounds currently being tested in clinical trials are showing promise in advanced kidney cancer. The molecular targets of these drugs include interfering with the vascular endothelial growth factor receptors or the raf kinase pathway, angiogenesis inhibition, and antimicrotubule agents. A review of the preclinical and early clinical development of some of these novel compounds will be discussed.