According to the results of two phase III clinical trials presented at the 2006 annual meeting of the American Society of Clinical Oncology (ASCO), the targeted therapies sunitinib and temsirolimus are more effective than interferon-alfa in the first-line treatment of metastatic renal cell cancer (RCC).
The kidneys are each filled with tiny tubules that clean and filter the blood-the process that removes waste and makes urine. Renal cell cancer (RCC) is a malignancy involving these tubules of the kidney. Metastatic RCC refers to cancer that has spread from the kidney to distant sites in the body.
Targeted therapies such as sunitinib, temsirolimus, and sorafenib have produced promising results in the treatment of metastatic RCC. Sunitinib and sorafenib were recently approved by the FDA for the treatment of advanced RCC. Temsirolimus has not yet been FDA approved. The benefits of these treatments continue to be explored.
To compare sunitinib to interferon-alfa (IFN-?) in the treatment of metastatic RCC, researchers conducted a phase III clinical trial among 750 patients who had received no prior systemic therapy. Half the patients were randomized to treatment with sunitinib and half were randomized to treatment with IFN-?.
- Compared to treatment with IFN-?, treatment with sunitinib significantly improved survival without cancer progression. Median survival without cancer progression was five months among patients treated with IFN and 11 months among patients treated with sunitinib.Currently, there is no significant difference in overall survival between the study groups, but the researchers note that a survival benefit may become apparent with longer follow-up. 37% of patients treated with sunitinib experienced at least a partial reduction in detectable cancer, compared to 9% of patients treated with IFN-?.
The second study compared three treatment groups: 1) treatment with IFN-?, 2) treatment with temsirolimus, or 3) treatment with a combination of the two agents. The study enrolled 626 patients with poor-prognosis stage IV or recurrent RCC.
- Compared to treatment with IFN-?, treatment with temsirolimus alone significantly improved overall survival. Overall survival was 7.3 months among patients treated with IFN-? and 10.9 months among patients treated with temsirolimus. Treatment with the combination of temsirolimus and IFN-? did not significantly improve overall survival.Survival without cancer progression was significantly better in the temsirolimus-alone group and the temirolimus plus IFN-? group. Survival without cancer progression was 1.9 months in the IFN group, 3.7 months in the temsirolimus-alone group, and 3.7 months in the temsirolimus plus IFN-? group.
- Temsirolimus alone was better tolerated than the combination of temsirolimus plus IFN-?.
These studies indicate that both sunitinib and temsirolimus are more effective than interferon-alfa in the first-line treatment of metastatic renal cell cancer.
 Motzer RJ, Hutson TE, Tomczak P et al. Phase III Randomized Trial of Sunitinib Malate (SU11248) Versus Interferon-Alfa (IFN-?) as First-Line Systemic Therapy for Patients with Metastatic Renal Cell Carcinoma (mRCC). Presented at the 2006 ASCO Annual Meeting. Abstract number LBA3.
 Hudes G, Carducci M, Tomczak P et al. A Phase III, Randomized, 3-arm study of Temsirolimus (TEMSR) or Interferon-alfa (IFN) or the Combination of TEMSR+IFN in the Treatment of First-line, Poor-prognosis Patients with Advanced Renal Cell Carcinoma. Presented at the 2006 ASCO Annual Meeting. Abstract number LBA4.