Using Molecular Biology to Develop Drugs for Renal Cell Carcinoma

BACKGROUND: Renal cell carcinoma is a disease marked by a unique biology which has governed it's long history of poor response to conventional cancer treatments. The discovery of the signaling pathway activated as a result of inappropriate constitutive activation of the hypoxia inducible factors (HIF), transcription factors physiologically and transiently stabilized in response to low oxygen, has provided a primary opportunity to devise treatment strategies to target this oncogenic pathway. OBJECTIVE: A review of the molecular pathogenesis of renal cell cancer as well as molecularly targeted therapies, both those currently available and those in development, will be provided. In addition, trials involving combination or sequential targeted therapy are discussed. METHODS: A detailed review of the literature describing the molecular biology of renal cell cancer and novel therapies was performed and summarized. RESULTS/CONCLUSION: Therapeutics targeting angiogenesis have provided the first class of agents which provide clinical benefit in a large majority of patients and heralded renal cell carcinoma as a solid tumor paradigm for the development of novel therapeutics. Multiple strategies targeting this pathway and now other identified pathways in renal cell carcinoma provide numerous potential opportunities to make major improvements in treating this historically devastating cancer.

Targeting vascular endothelial growth factor (VEGF)-receptor-signaling in renal cell carcinoma

Metastatic renal cell carcinoma (RCC) is resistant to conventional chemotherapy. Combined data for a variety of immunotherapies resulted in an overall chance of partial (PR) or complete remission (CR) of only 12.9%. There is a clear need for novel, more effective therapies to prevent relapse, control metastases and improve overall survival. Improved understanding of RCC disease biology has led to the introduction of molecularly targeted treatment strategies in these cancers. Von Hippel-Lindau (VHL) gene inactivation is observed in most clear cell renal carcinoma, resulting in vascular endothelial growth factor (VEGF) over-expression and driving the malignant phenotype. This review discusses the efficacy of novel therapies targeting the VEGF receptor (VEGFR) (e.g. anti-VEGF antibodies, VEGFR tyrosine kinase inhibitors, mTOR inhibitors), some of which were recently approved by the Food and Drug Administration/European Medicines Evaluation Agency (FDA/EMEA) and represent the new treatment standards in RCC patients.