Renal cell carcinoma is the most common kidney cancer with an incidence increasing in developed countries. One-third of patients already present metastatic disease at diagnosis. The treatment consists of targeted therapies, such as sunitinib a tyrosine kinase inhibitor, that is considered one of the first line treatment for metastatic stage. However, due to development of resistance, treatments do not provide long term efficacy as monotherapies. CPI-613 is a novel class of anticancer agents targeting mitochondria, that has shown promising results in clinical studies when combined with chemotherapy for pancreatic cancer and acute myeloid leukemia. The aim of this study is to evaluate the effect of the combination of CPI-613 and sunitinib in renal cell carcinoma (RCC) cell lines. The hypothesis being that the combination with sunitinib will generate toxic levels of reactive oxygen species (ROS) that will inhibit cell viability. The treatments were performed on three RCC cell lines, namely Caki-1, A498 and 786-0. The sensitivity of the cell lines to each drug was evaluated by cell viability assay in order to select concentrations. The effects of the combination of the two drugs were assessed by MTS assay, crystal violet coloration and cell counting. Results showed that cells were sensitive to CPI-613 and sunitinib alone and in combination, CPI-613 enhanced sunitinib inhibition effect on cell viability. The role of oxidative stress in the inhibition of cell viability was then evaluated. Cellular oxidative stress level was demonstrated by ROS assay and the protective effects of antioxidant molecule N-acetylcysteine was tested by ROS assay and MTS assay. The results showed that oxidative stress wasn’t the cause of cell death. Preliminary studies on the effect of the drugs alone and in combination on cell death pathway and cell cycle were then effectuated. Blockage of apoptosis and necrosis by respectively Z-VAD-FMK and Necrostatin-1 effects on cell viability were evaluated, showing that the pathway blockage did not save the cells suggesting that cell death is none of these types. Cell cycle was then analyzed by flow cytometry and results suggested that phase cycle arrest depended on the cell line treated and that cell death was not caused by fragmentation of DNA. Western blot analysis on the regulatory cleavage of caspase-3 and PARP inducing apoptosis were conducted in parallel but were not conclusive.