ABSTRACT
Introduction: Nivolumab is a PD-1 checkpoint inhibitor that restores the pre-existing antitumor immune response by selectively blocking the interaction between PD-1 receptors on T-cells and PD-1 ligands, PD-L1 and PD-L2, on tumor cells and antigen presenting cells. Nivolumab prolongs survival in patients with metastatic kidney cancer with a good safety profile as demonstrated in the CheckMate 025 clinical trial. Material And Methods: This retrospective data involved prospectively monitored patients (named patient programm) treated with second-line nivolumab for mRCC at the University Hospital Centre Zagreb from 2016 to 2018 and the treatment continued to be funded by the Croatian Health Insurance. Patients with metastatic kidney cancer (mRCC) received tyrosine kinase inhibitors (TKI), (29/30), one patient received mTOR inhibitor as first line therapy, and subsequently they initially received nivolumab 3 mg kg NPP every 2 weeks. Later we applied a monthly dose 480 mg. Nivolumab treatment was continued in patients who did not have disease progression or grade 3 and 4 toxicity. Patients were monitored every three momths with CT of the chest, abdomen and pelvis and laboratory tests (hemathology, biochemistry, T4, TSH). We also respected patients' preference in regard to cycle dynamic by stopping nivolumab therapy or introducing SBRT during nivolumab therapy. Results: We treated a total of 30 patients (22 men and 8 women) with mRCC, who initially received TKI or mTOR therapy with median age 60.2 ± 9.79 years at diagnosis of kidney cancer. Most patients belonged to intermediate-risk groups. Majority of patients (23/30) were treated with sunitinib as the first line treatment after nephrectomy. Six patients had CR (20%) but two of them died in 2021, one of COVID- 19 and one of haed and neck cancer. Currently, 6 (20%) are alive, ECOG=0, 4 (13.3%) have CR without therapy, expressed in months-23, 33, 35 and 53 (treatment-free survival). Median OS first line with TKI therapy was 34 months while median OS second line with nivolumab was 17 months. Patients with sarcomatoid component in pathohistology report have longer survival. Patients with bone metastases have shorter survival to patients with other metastases. Conclusion: Nivolumab demonstrated clinical efficacy in the CheckMate 025 clinical trial and in clinical practice as second line treatment after patients had previously received TKI. Our results show that six years after first cycle of nivolumab as second line therapy 6 out of 30 patient (20%) are alive, ECOG=0. Further research should show which sequence therapy would be the best for each patient. Research about potential immunotherapy biomarkers which would indicate who responds to the therapy and who does not is ongoing.