New analyses from a phase III clinical trial of patients with previously treated advanced kidney cancer demonstrated that patients of all risk levels experience more benefit from cabozantinib than from the current standard of care everolimus.
The greater activity of cabozantinib was independent of metastatic sites, the number of prior treatments, and the type of treatments administered.
“Current treatments can provide some benefit to patients with advanced kidney cancer, but we need treatments that are more effective,” said lead study author Bernard Escudier, MD, Chair of the Genitourinary Oncology Committee at the Institut Gustave Roussy in Villejuif, France.
“Our preliminary results suggest that cabozantinib may help overcome treatment resistance and provide new hope to patients with this aggressive cancer.”
Renal cell carcinoma (RCC) is the most common type of kidney cancer, and its incidence is increasing worldwide.
Standard treatments include two classes of targeted drugs: vascular endothelial growth factor receptor (VEGFR) inhibitors and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus.
Cabozantinib blocks the growth of tumour blood vessels and the key signalling pathways that drive tumour growth and spread.
In the trial, 658 patients with advanced RCC who had previously received VEGFR inhibitor therapy were randomly assigned to receive cabozantinib or everolimus.
Early findings from the first 375 patients showed that cabozantinib improved the median progression-free survival compared to everolimus (7.4 months vs. 3.8 months).
The new analysis of data from all 658 patients showed that the great majority (75%) of patients treated with cabozantinib experienced tumour shrinkage, compared to 48% of everolimus-treated patients.
In addition, an early evaluation of overall survival showed a trend for improved survival for patients receiving cabozantinib compared to everolimus.
Researchers found that progression-free survival improvements associated with cabozantinib versus everolimus were consistent across patient subgroups.
The subgroups were defined by risk category (favourable, intermediate, or poor risk), tumour burden, and prior therapy (type, number, and duration).
Furthermore, researchers found that patients who had liver metastases or a combination of visceral and bone metastases also benefited more from cabozantinib.
The most common side effects related to cabozantinib were diarrhoea, fatigue, nausea, decreased appetite, and hand- foot syndrome (a condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet).
The most common side effects associated with everolimus included fatigue, anaemia, decreased appetite, cough, and dyspnea (difficult breathing or shortness of breath).
Treatment side effects were successfully managed with supportive care and dose modifications.
Cabozantinib is currently FDA approved for treatment of patients with a specific form of thyroid cancer.
It is being tested in clinical trials for a wide range of cancer types.
(25 May 2016)