According to a recent article published in the International Journal of Cancer, the addition of thalidomide may increase the effectiveness of Proleukin® (interleukin 2) in patients with renal cell cancer that has stopped responding to prior therapy with Proleukin®.
The kidneys are a pair of bean-shaped organs located on each side of the spine. The kidneys filter the blood and eliminate waste in the urine through a complex system of filtration tubules. All of the blood in the body passes through the kidneys approximately 20 times an hour. Renal cell cancer (RCC) is an uncommon form of cancer that is most often characterized by the presence of cancer cells in the lining of the filtration tubules of the kidney. Metastatic RCC refers to cancer that has spread outside the kidney to several and/or distant sites in the body. Proleukin® is a biologic agent that enhances the immune system to help fight cancer, and is the only agent approved for the treatment of metastatic RCC.
Although patients with metastatic RCC may experience an initial anti-cancer response to Proleukin®, a large portion of patients may ultimately experience a cancer recurrence. These patients have limited effective therapeutic options and researchers continue to evaluate novel therapeutic agents or combinations of agents to improve the outcome of patients with this disease. Thalidomide, with properties that appear to stimulate the immune system as well as decrease the extension of blood vessels and blood flow to tumors, has been evaluated in various cancers, including RCC. Researchers speculated that due to the biologic properties of Proleukin® and thalidomide, the combination of these agents may provide improved anti-cancer responses for the treatment of RCC.
Researchers from Israel recently conducted a small clinical trial evaluating the combination of Proleukin® plus thalidomide in patients with metastatic RCC whose cancer had recurred and continued to grow following previous therapy with Proleukin®. This trial only included 4 patients who were re-treated with the same regimen of Proleukin® they had received previously, with the addition of thalidomide. Of these patients, 2 (50%) experienced an anti-cancer response, and the other 2 (50%) experienced a prolonged stabilization of their cancer.
The researchers concluded that the addition of thalidomide appears to increase the effectiveness of Proleukin® in patients with RCC that have stopped responding to initial therapy with Proleukin®, as all patients experienced a response. Since this trial only included 4 patients, the researchers propose that larger clinical trials evaluating Proleukin® plus thalidomide are warranted. Patients with RCC that has stopped responding to previous treatment with Proleukin® may wish to speak with their physician about the risks and benefits of participating in a clinical trial evaluating Proleukin® plus thalidomide or other novel therapeutic approaches.
Reference: Kedar I, Mermershtain W, and Ivgi H, Thalidomide Reduces Serum C-Reactive Protein and Interleukin-6 and Induces Responses to IL-2 in a Fraction of Metastatic Renal Cell Cancer Patients who Fail IL-2 Based Therapy. International Journal of Cancer. 2004; Advanced publication on line 2/19/04.