Nivolumab in patients with metastatic renal cell carcinoma and chronic hepatitis C virus infection

Background Hepatitis C virus (HCV) interferes with activation of innate and adaptive immune responses. Theoretically, the efficacy and toxicity of immune checkpoint inhibitors in cancer patients infected with HCV may differ. Nevertheless, HCV was an exclusion criterion in most checkpoint inhibitor trials. We evaluated the efficacy and safety of nivolumab in metastatic renal cell carcinoma (mRCC) patients with or without chronic HCV infection. Methods In a matched cohort study, data were collected from 174 patients, retrospectively. All patients had clear-cell mRCC, chronic HCV infection (case study group), no evidence of other malignancy or cirrhosis, and had received nivolumab (3 mg/kg every 2 weeks) until disease progression or unacceptable toxicity. Quantitation of HCV RNA in plasma samples was performed before and during treatment with nivolumab with the automated HCV test (Hoffmann-La Roche, Switzerland). The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and rate of grade 3-4 adverse events in study and control cohorts. Results A total of 44 matched patients were included. Groups were well balanced. HCV-infected patients had significantly longer OS and PFS. Median OS was 27.5 (95% CI 25.3-29.7) and 21.7 (20.3-23.1) in study and control groups, respectively (P = 0.005). Median PFS was 7.5 (5.7-9.3) and 4.9 (4-5.8) (P = 0.013). Despite no differences in ORR between groups (27% vs. 23%, P = 0.7), patients with HCV had significantly more durable responses (P = 0.01). Nivolumab was well tolerated in all HCV-positive patients. No unexpected toxicity was observed. Assessment of viral load during nivolumab therapy was available in 14 of 22 (64%) patients with HCV. Nivolumab did not significantly impact HCV concentration (mean change 210 IU/ml, P = 0.82) in the absence of antiviral therapy. Conclusions The efficacy and safety profiles observed in this study support the administration of nivolumab in mRCC patients infected with HCV and warrant further investigation.