Outcome of metastatic renal cell carcinoma (MRCC) patients treated by anti-PD-1 therapy in expanded access program: clinical efficacy and potential biomarkers for nivolumab therapy

Therapy with immune checkpoints inhibitors (anti-PD-1 therapy) has become the standard of care for metastatic renal cell carcinoma (mRCC) patients with resistance to tyrosine kinase inhibitors (TKI). Identification of reliable predictive markers for anti-PD-1 therapy would help to select patients who are most likely to respond to checkpoints inhibitors. This article represents the results of treatment of 23 mRCC patients who received nivolumab as part of the expanded access program in Russia. All patients demonstrated resistance to previous lines of TKI therapy. Overall response rate for nivolumab was 21.7 % with median progression-free survival of 4 months (95%CI=1.37-10.04). The median overall survival was not reached with the median follow-up of 10 months (3-14 months). The grade 3-4 toxicity was observed in 3 (13 %) pts. Favorable MSKCC prognosis before treatment, the initial level of sPD-1 exceeding the estimated threshold value and the development of any grade hypothyroidism after treatment initiation were associated with greater progression free survival. The number of preceding lines of TKI therapy, the level of PD-L1 and FOXP3 expression on tumor-infiltrating leukocytes (TILs) did not significantly affect progression-free survival in this group of mRCC patients. The efficacy and toxicity profile of nivolumab corresponded to the results of phase 2-3 trials.