Camrelizumab with or without Autologous Cytokine-induced Killer Cell Therapy in Patients with Refractory Clear Cell Renal Cell Carcinoma: A Randomized Pilot Study

Clear cell renal cell carcinoma (ccRCC) remains a challenging malignancy to treat, with immune checkpoint inhibitors (ICIs) revolutionizing patient management. This clinical study, involving a small cohort, evaluated the efficacy and safety of combination therapy comprising camrelizumab, an anti-PD-1 antibody, and autologous cytokine-induced killer (CIK) cell therapy in patients with refractory ccRCC. Twenty-one patients with refractory ccRCC were randomly assigned to receive either camrelizumab monotherapy (control group, n = 12) or camrelizumab combined with CIK cell re-transfusion (trial group, n = 9). The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety were evaluated. Biomarker exploration was performed using peripheral blood samples from patients. A trend towards a higher ORR was observed in the trial group (55.6%) compared to the control group (41.7%). Favorable trends were also noted for median PFS (28.50 vs. 8.67 months) and median OS (not reached vs. 57.47 months) in the trial and control groups, respectively. One patient in the trial group achieved a complete metabolic response (CMR). No new safety signals were observed, and CIK cell re-transfusion did not appear to increase the frequency of adverse effects. Exploratory analysis suggested that higher baseline PD-1 expression on CD8 ⁺ T cells might be associated with a better response, and the frequency of PD-1 positive cells tended to decrease after camrelizumab administration. The addition of CIK cell therapy to anti-PD-1 antibody showed encouraging signals of antitumor activity in refractory ccRCC with a tolerable safety profile. These preliminary findings warrant further investigation, which could focus on the combination of ICIs, antiangiogenic agents, and CIK cell re-transfusion as a potential first-line therapy for metastatic or advanced ccRCC.Registry: ClinicalTrials.gov, TRN: NCT03987698, Registration date: 17 June 2019.