by Dr. C.H. Weaver M.D. updated 2/2019
The United States Food and Drug Administration (FDA) has approved the kinase inhibitor Cabometyx™ (cabozantinib) for the treatment of renal cell carcinoma (kidney cancer) in the first line setting. The FDA previously approved Cabometyx in 2016 for treatment of patients with advanced RCC who have received prior anti-angiogenic therapy.
Cabometyx™ is a kinase inhibitor that stops or decreases the action of many different cellular processes involved in cancer growth or spread. Cabometyx™ is thought to inhibit the action of the receptor tyrosine kinases including MET, VEGFR-1, -2, and -3, AXL, RET, ROS1, TYRO3, MER, KIT, TRKB, FLT-3, and TIE-2.
The approval as initial treatment for advanced renal cell cancer was based on data from CABOSUN (NCT01835158), a comparative clinical trial performed in 157 patients with intermediate and poor-risk previously untreated cancer. Patients were treated with either Cabometyx or Sutent (sunitinib)) and directly compared. The estimated median progression-free survival for patients taking Cabometyx was 8.6 months.
Approval in Patients who Have Received Prior Anti-angiogenic Therapy
This approval of Cabometyx™ was based on a trial including approximately 660 patients with advanced RCC who had received prior therapy with an anti-angiogenic agent. Patients in the trial were treated with either Cabometyx™ or the standard treatment agent, Afinitor® (everolimus).
- Anti-cancer responses were achieved in 17% of patients treated with Cabometyx™, compared with only 3% of patients treated with everolimus.
- Median survival time without progression of cancer was 7.4 months for patients treated with Cabometyx™, compared with 3.8 months for those treated with everolimus.
- Median overall survival time was 21.4 months for patients treated with Cabometyx™, compared with 16.5 months for patients treated with everolimus.
The most common serious side effects associated with Cabometyx™ were abdominal pain, excess fluid buildup around the lungs (pleural effusion), diarrhea, and nausea.
The approval of Cabometyx™ provides an additional treatment option for patients with advanced RCC, demonstrating improved outcomes compared to the historical standard therapy.
Cabometyx is also approved for the treatment of medullary thyroid cancer and is marketed under the trade name Cometriq. Cometriq and Cabometyx have different formulations and are not interchangeable.
About Renal Cell Cancer
Each year in the United States, more than 61,000 people are diagnosed with kidney cancer. The most common type of kidney cancer is renal cell carcinoma (RCC), which starts in the lining of very small tubes (tubules) in the kidney. For people with advanced or metastatic RCC (cancer that has spread to other parts of the body), targeted therapies can play an important role in treatment. Approximately 20-30% of patients with RCC will have metastases at diagnosis and as many as 40% will demonstrate metastasis after treatment for earlier stage RCC. With a 5-year survival rate ranging from 5-10% for patients with advanced RCC, the overall prognosis for these patients is poor.