The use of tyrosine kinase inhibitors (TKIs) sunitinib and pazopanib to treat metastatic clear cell renal cell carcinoma (RCC) is feasible and effective in Brazil, even though limitations of the public health system mean not all patients have access to these or other therapies, researchers wrote.
In a retrospective analysis of 222 patients with advanced clear cell RCC who were treated with either sunitinib (n = 109) or pazopanib (n = 113), overall survival was 15.2 months with sunitinib and 14.2 months with pazopanib, investigators reported in the.
Overall survival rates, based on Memorial Sloan Kettering Cancer Center risk categories, were 32.9 months for patients with low risk disease, 15.9 months for intermediate risk patients, and 8.1 months for patient with poor risk – which constituted 29% of the patient population.
Pedro I. Velho, MD, of Johns Hopkins University, Baltimore, and his coauthors noted that these survival rates were lower than those seen in phase 3 trials in the same population.
They suggested this could be caused by the fact that the patients in this real-world study had worse baseline prognoses than those seen in previous clinical trials.
However, they also pointed out that, in the Brazilian public health system, there was no standard systemic treatment option outside clinical trials for patients who have progressed on a TKI as a first-line treatment. Only around half the patients in this study (101) would have been eligible for participation in a clinical trial.
“In our opinion, it is crucial to extend the access to these TKIs for the Brazilian population and also patients in other countries with limited access to targeted therapies,” the authors wrote.
However, the 14 patients who were eligible for treatment with nivolumab under a compassionate use program showed a significantly better overall survival rate, compared with patients who did not have access to a second-line therapy (36.7 months vs. 13.6 months; P less than .001).
“Also, it is imperative to provide systemic sequential treatment options for this population as an attempt to improve survival and offer the best outcomes for patients with metastatic RCC.”
The median duration of treatment with sunitinib was 6.4 months, and with pazopanib, it was 6.7 months. Adverse events were responsible for discontinuation of treatment in 28.4% of patients on sunitinib and 22.1% of patients on pazopanib, with fatigue, diarrhea, nausea and vomiting as the most common toxicities in both groups.
Six authors declared honoraria, funding, expenses or consultancies with the pharmaceutical industry. Two authors had no conflicts of interest to declare.
SOURCE: Velho PI et al. J Glob Oncol. 2018 Sep 10. .