High Complete Response Rate in Patients With Metastatic Renal Cell Carcinoma Receiving Autologous Cytokine-Induced Killer Cell Therapy Plus Anti-Programmed Death-1 Agent: A Single-Center Study

BACKGROUND AND OBJECTIVE: The results of the CheckMate 025 trial established the status of nivolumab in the second-line treatment of metastatic renal cell carcinoma (mRCC), with an objective response rate (ORR) of 25% and a complete response (CR) rate of 1%. Thus, the efficacy of anti-programmed death (PD)-1 antibodies in the second-line treatment of mRCC requires improvement. The purpose of this study was to explore the clinical efficacy and safety of anti-PD-1 agents combined with cytokine-induced killer (CIK) cell therapy for refractory mRCC. PATIENTS AND METHODS: Patients with mRCC refractory to previous targeted therapy were included in this study. All patients received anti-PD-1 plus CIK cell therapy. The ORR and CR rate, progression-free survival (PFS), overall survival (OS), and safety were assessed. RESULTS: CR was observed in seven of the 29 patients, and partial response was observed in five patients. The ORR was 41.4% and the median PFS was 15.0 months. Up to the last follow-up, 15 patients died with an average survival time of 37 months. Among the patients who achieved a CR, one experienced cerebellar metastasis 18.8 months after discontinuation, but achieved CR again after localized gamma knife and 1-month axitinib treatment. This regimen was tolerated well and there was no treatment-related death. CONCLUSIONS: Combination therapy with anti-PD-1 and CIK cell therapy is safe and effective in patients with mRCC refractory to previous targeted therapy. The high CR rate and long disease-free survival even after long-term discontinued therapy suggest that this combination treatment may represent a potential curative regimen for this type of malignancy.