First-line therapy with cabozantinib was superior to standard of care sunitinib with respect to progression-free survival and objective response rate for patients with intermediate- or poor-risk metastatic renal cell carcinoma (mRCC), according to a study published in the Journal of Clinical Oncology.
Cabozantinib is a tyrosine kinase inhibitor (TKI) approved for treatment of patients with advanced mRCC who have received prior anti-angiogenic therapy, such as sunitinib. Both TKIs stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.
The randomized phase II study, sponsored by the National Cancer Institute, examined how well cabozantinib, in comparison with sunitinib, treated patients with previously untreated kidney cancer that had spread from its original location to nearby tissue or lymph nodes in the body. Researchers sampled 157 patients with intermediate- or poor-risk, untreated mRCC. The patients were randomly assigned 1:1 to receive either oral cabozantinib daily continuously or oral sunitinib daily for a 4-weeks-on, 2-weeks-off cycle.
Researchers found cabozantinib improved progression-free survival and objective response rate. Cabozantinib significantly reduced the risk of progression or death by 34% compared with sunitinib. Median progression survival for patients treated with cabozantinib was 8.2 months, compared with 5.6 months for patients treated with sunitinib. Researchers also found that 46% of patients treated with cabozantinib achieved an objective response, compared with 18% of patients treated with sunitinib.
Adverse events were similar between the patients in both groups. The rate of all-cause grade 3 to 4 adverse events was 67% for cabozantinib, with the most common events being hypertension and palmar-plantar erythrodysesthesia, and 68% for sunitinib, with the most common events being fatigue and hematologic toxicities.
The findings suggest that cabozantinib may be considered as a first-line treatment option for patients with intermediate- or poor-risk, previously untreated mRCC. More research is necessary to determine cabozantinib’s effects on overall survival rates among these patients.