Sunitinib or Pazopanib: Is There Any Difference Between Tyrosine Kinase Inhibitors in the Pre-Nivolumab Setting in Metastatic Renal Cell Carcinoma?

Prognostic value of type of prior TKI in pretreated metastatic renal cell carcinoma patients receiving nivolumab

Aim: To define the prognostic significance of first-line TKI in mRCC patients receiving nivolumab.Materials and methods: A total of 571 mRCC patients who received ≥second line nivolumab were included in this subanalysis. The correlation between prior TKI (sunitinib vs. pazopanib) and overall response rate (ORR), disease control rate, progression-free survival and overall survival were investigated. Additionally, the impact of TKI choice according to the International Metastatic RCC Database Consortium prognostic score was examined.Results: There was no significant difference between sunitinib and pazopanib groups in terms of mPFS, mOS, overall response rate and disease control rate. Moreover, no difference between sunitinib and pazopanib was found according to the International Metastatic RCC Database Consortium prognostic score.Conclusion: There is no conclusive evidence favoring pazopanib or sunitinib treatment before initiating nivolumab therapy in metastatic renal cell carcinoma patients.

Sunitinib versus Pazopanib Dilemma in Renal Cell Carcinoma: New Insights into the In Vitro Metabolic Impact, Efficacy, and Safety

Sunitinib and pazopanib are tyrosine kinase inhibitors (TKIs) used as first-line therapy for metastatic renal cell carcinoma (RCC). Although these TKIs are associated with similar survival outcomes, some differences have been reported in their safety profiles. In this work, traditional toxicological endpoints (cell viability and growth, oxidative stress, and nuclear morphology) and 1H NMR spectroscopy-based metabolomics analysis were used to provide new insights into the cytotoxicity and metabolic mechanisms underlying sunitinib and pazopanib treatments. Tumoral (Caki-1) and non-tumoral (HK-2) human renal cells were exposed to clinically relevant concentrations of sunitinib (2 µM) or pazopanib (50 µM). Sunitinib showed selectivity for cancer cells, inhibiting proliferation, and inducing apoptotic death of Caki-1 cells, whereas pazopanib had a similar cytotoxic effect in both tumoral and non-tumoral cells. 1H-NMR metabolomics unveiled a higher impact of sunitinib on the levels of intracellular metabolites of Caki-1 cells (seven dysregulated metabolites), suggesting dysregulations on amino acid, glutathione and glycerophospholipid metabolisms. In contrast, pazopanib had a higher impact on the levels of extracellular metabolites of Caki-1 cells (seven dysregulated metabolites in culture medium), unveiling alterations on amino acid and energetic metabolisms. In HK-2 cells, sunitinib caused only a minor increase in intracellular isoleucine levels, whereas pazopanib induced several alterations on the intracellular (three dysregulated metabolites) and extracellular (three dysregulated metabolites) compartments suggesting changes on amino acid, glycerophospholipid, and energy metabolisms. Our results demonstrate that these TKIs elicit distinct cellular and metabolic responses, with sunitinib showing better in vitro efficacy against target RCC cells and lesser nephrotoxic potential than pazopanib.