Randomized pilot study of camrelizumab with or without autologous cytokine-induced killer cells in refractory clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) remains a challenging malignancy to treat, with immune checkpoint inhibitors (ICIs) revolutionizing patient management. This pilot study, 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). Due to early termination (21 of 60 planned patients), all endpoints were exploratory. The objective response rate (ORR) was numerically higher in the combination group (55.6% vs. 41.7%; odds ratio 1.75, 95% confidence interval [CI]: 0.32-9.51), but not statistically significant. Median progression-free survival (PFS) was 28.5 vs. 8.67 months (hazard ratio [HR] 0.40, 95% CI: 0.12-1.34), and median overall survival (OS) was not reached vs. 57.47 months (HR 0.48, 95% CI: 0.09-2.53). One patient in the trial group achieved a complete metabolic response (CMR). The combination was well-tolerated without new safety signals. 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 signals of potential benefit in refractory ccRCC with a tolerable safety profile. This pilot study suggests the combination approach appears feasible and warrants investigation in larger trials in pretreated ccRCC patients.Registry: ClinicalTrials.gov, TRN: NCT03987698, Registration date: 17 June 2019.