Findings from a federally funded study suggest that patients with locally advanced kidney cancer should not be treated with either adjuvant (post-surgery) sorafenib or sunitinib. The average period to disease recurrence was similar between those who received sorafenib or sunitinib after surgery (5.6 years) and those treated with placebo (5.7 years). The study will be presented at the upcoming 2015 Genitourinary Cancers Symposium in Orlando.
"These drugs didn't reduce disease recurrence, but on average they did not appear to worsen patient outcomes either," said lead study author Naomi B. Haas, MD, an Associate Professor of Medicine at the Abramson Cancer Center of the University of Pennsylvania in Philadelphia, Pa. "We are still analyzing the various groups of patients enrolled on this trial, and we hope that analysis of patient specimens collected on this study may provide clues into subsets of patients who might still benefit from these therapies."
Sorafenib and sunitinib are VEGF inhibitors, a class of drugs that work by blocking the growth of blood vessels to the tumor. They are widely used for the treatment of metastatic kidney cancer.
According to the authors, this is the first and largest trial reporting on the efficacy of VEGF inhibitors as adjuvant therapy for patients with locally advanced kidney cancer who are at high risk of recurrence. The current standard of care for such patients is close observation.
After undergoing surgery, 1,943 patients with locally advanced renal cell carcinoma were randomly assigned to receive sorafenib, sunitinib, or placebo for one year. All patients were at high risk of recurrence based on factors such as tumor size and grade, and cancer spread to lymph nodes.
At interim analysis, recurrence rates (about 40 percent) and the disease-free survival (5.6-5.7 years) were similar between all three treatment regimens. Researchers continue to follow patients to document recurrence and survival.
Dr. Haas stated that the large specimen collection required for this trial will be an invaluable resource in the mission to cure kidney cancer. It will provide molecular clues to identify individuals that may benefit from these treatments and help researchers learn more about therapy resistance and disease recurrence.
Adjuvant treatment of locally advanced kidney cancer is an area of active research. Several trials using other VEGF inhibitors have finished accruing patients and are awaiting analysis. Ongoing clinical trials exploring another VEGF inhibitor, axitinib, and the mTOR inhibitor everolimus are still accruing patients. Trials using immunotherapy and other targeted therapy approaches are being planned.