Adjuvant Anti-VEGF Drugs Unhelpful in Locally Advanced Kidney Cancer

By Megan Brooks

NEW YORK (Reuters Health) - Adjuvant treatment with either sorafenib (Nexavar) or sunitinib (Sutent) is unhelpful in locally advanced resected kidney cancer and should not be pursued, researchers said today.

Initial results from the ASSURE study show that neither drug reduced disease recurrence, according to lead investigator Dr. Naomi B. Haas of the Abramson Cancer Center of the University of Pennsylvania in Philadelphia.

She reported the results during a press briefing ahead of the 2015 Genitourinary Cancers Symposium in Orlando, Florida, where she will present the data. The symposium is sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology and the Society of Urologic Oncology.

Sorafenib and sunitinib are tyrosine kinase inhibitors (TKIs) that also inhibit VEGF and are used widely in metastatic kidney cancer. The ASSURE study is the first and largest trial assessing the efficacy of VEGF inhibitors as adjuvant therapy for patients with locally advanced kidney cancer who are at high risk of recurrence. Currently the standard of care is to monitor patients for recurrence.

The study enrolled 1,943 patients with locally advanced completely resected renal cell carcinoma, with random allocation to sunitinib (n=647), sorafenib (n=649), or placebo (n=647) for up to one year.

The treatment arms were "well balanced" in terms of the type of kidney cancer, the type of surgery, the patient's performance status, and the risk for recurrence, Dr. Haas said.

There were no marked differences in the percentage of patients alive at five years without recurrence (53.8% in the sunitinib arm, 52.8% with sorafenib and 55.8% in the placebo arm).

Median disease-free survival was 5.6 years in patients who received sorafenib or sunitinib and 5.7% in those who received placebo after surgery.

"The overall survival was between roughly 77% and 81% in all treatment groups and again essentially there was no difference (between groups) in this initial assessment," Dr. Haas reported.

"The findings from this study suggest that patients with locally advanced kidney cancer completely resected should not be treated with sorafenib or sunitinib," she said.

Ongoing analysis of patient specimens collected on this study "may provide clues into subsets of patients who might still benefit from these therapies," Dr. Haas noted in a statement.

Briefing moderator Dr. Charles Ryan, ASCO expert with the Helen Diller Family Comprehensive Cancer Center in San Francisco, said, "This is a very important study . . . and the fact that it is a negative study in no way diminishes the importance of it. It's important to point out that TKIs are not chemotherapy, they act in a different manner and therefore they may not be as effective against micro metastatic disease as chemotherapy is in other solid tumors."

This study received funding from the National Institutes of Health.

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