Tailoring treatment with cabozantinib or pazopanib in patients with metastatic renal cell carcinoma: does it affect outcome?

Background: Metastatic renal cell carcinoma (mRCC) treatment is still largely based on TKI use. Treatment adjustment due to toxicities is often needed. The aim of the present study was to determine the impact of treatment modifications on the outcome of mRCC patients treated with cabozantinib or pazopanib. Research design and methods: This retrospective multicenter study enrolled consecutive patients receiving cabozantinib or pazopanib between January 2012 and December 2020. We evaluated the correlation of TKI treatment modifications with grade 3-4 toxicities and progression-free (PFS) and overall survival (OS). We also performed a landmark analysis excluding patients who did not undergo at least 5 months of therapy. Results: Among 301 patients, 179 (59%) were treated with pazopanib, 122 (41%) with cabozantinib. Treatment modifications were related to grade 3-4 toxicities (p < 0.0001). We observed a statistically significant longer PFS and OS in patients who underwent dose reductions (p < 0.0001 for both PFS and OS), temporary interruption (p < 0.0001 for both PFS and OS) and schedule modifications (p = 0.007 for PFS and p = 0.012 for OS) at univariate analysis. These results were confirmed at multivariable and landmark analyses. Conclusions: Tailoring treatment with pazopanib and cabozantinib was associated with better PFS/OS.