The Alliance for Clinical Trials in Oncology (the Alliance), in conjunction with industry partner Exelixis, today announced that the U.S. Food and Drug Administration (FDA) approved CABOMETYX (cabozantinib) tablets for the expanded indication of patients with advanced renal cell carcinoma (RCC). RCC is the most common form of kidney cancer in adults. The FDA's priority review and approval of cabozantinib was based on results from the Alliance randomized phase II CABOSUN trial in patients with previously untreated RCC, which demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) versus sunitinib, a current standard of care. Today's label expansion follows the initial FDA approval of cabozantinib in April 2016 for the treatment of patients with advanced RCC who have previously received anti-angiogenic therapy.
"The CABOSUN trial enrolled treatment-naïve patients with advanced kidney cancer, including those who are known to fare poorly, such as patients with intermediate- or poor-prognostic factors and those with bone metastases or multiple sites of metastatic disease," said Toni Choueiri, MD, Director, Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute and chair of the CABOSUN study. "Physicians are already experienced in using cabozantinib in the second-line advanced RCC setting, and it is a much-needed advance to also now have cabozantinib as an option for their patients with previously untreated advanced RCC."
The expanded approval of cabozantinib is based on results of the phase II CABOSUN trial, which met its primary endpoint of improving PFS. According to the independent radiology review committee analysis of the data, cabozantinib demonstrated a clinically meaningful and statistically significant 52 percent reduction in the rate of disease progression or death (HR 0.48, 95% CI 0.31-0.74, two-sided P=0.0008). Median PFS for cabozantinib was 8.6 months versus 5.3 months for sunitinib, corresponding to a 3.3-month (62 percent) improvement.
All causality Grade 3 or 4 adverse reactions occurred in 68 percent of patients receiving cabozantinib and 65 percent of patients receiving sunitinib. The most frequent all causality Grade 3-4 adverse reactions (less than or equal to 5 percent) in patients treated with cabozantinib were hypertension, diarrhea, hyponatremia, hypophosphatemia, palmar-plantar erythrodysesthesia (PPE), fatigue, increased ALT, decreased appetite, stomatitis, pain, hypotension, and syncope. Twenty-one percent of patients in the cabozantinib arm compared to 22 percent of patients receiving sunitinib discontinued treatment due to adverse events.
"We at the Alliance are very gratified that the CABOSUN study supported the approval of cabozantinib for the potential first-line treatment of all patients with advanced renal cell carcinoma. This trial exemplifies how NCI-sponsored studies can be efficient, accrue rapidly, and yield results highly relevant to the field," said Michael J. Morris, MD, medical oncologist at Memorial Sloan Kettering Cancer Center, and Chair of the Alliance Genitourinary (GU) Committee.
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