Characteristics of patients with metastatic renal cell carcinoma who do not respond to axitinib treatment.

Background: Axitinib is a widely used tyrosine kinase inhibitor (TKI) in metastatic renal cell carcinoma (mRCC) treatment. Here, we analyzed the characteristics of patients who did not respond to axitinib and evaluated alternative options for their treatment.

Methods: We retrospectively analyzed data for 449 patients with mRCC who were administered axitinib following another TKI as initial therapy. Patients with progressive disease (PD) at their first assessment were defined as showing early-PD. We analyzed the characteristics of patients at risk of early-PD and evaluated the relationship between the treatment following axitinib and their prognosis.

Results: Early-PD was diagnosed in 102 patients, and was more common in those who had not undergone nephrectomy (p < 0.001), those treated with a TKI for a short period (p < 0.001), and those in the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) poor risk category for mRCC (p < 0.001). Multivariate analysis showed that these were independent risk factors for early-PD (all p < 0.001). Of those with early-PD, 52 changed to next-line treatment. The progression-free survival periods were 5.5 (95% confidence interval (CI) 2.4-8.6) months for patients administered TKIs, 4.2 (95% CI 0.3-8.1) months for those on nivolumab, and 2.2 (1.8-2.6) months for those on mammalian target of rapamycin inhibitors (p = 0.030).

Conclusion: Patients who have not undergone nephrectomy, those previously treated with another TKI for a short period, and those in the IMDC poor risk category are more likely to experience early-PD when taking axitinib. Furthermore, TKIs are the best treatment for patients with early-PD who have previously been administered axitinib.