Immune Checkpoint Inhibitors Suppress Hepatitis C Virus Replication in Infected Patients With Solid Tumors

Data are scarce regarding the virologic impact and safety of immune checkpoint inhibitors (ICI) in patients with chronic hepatitis C virus (HCV) infection. We examined the virologic impact of ICI in HCV-infected patients with solid tumors and their safety.

HCV-infected patients with solid tumor treated with ICI at our institution between April 26, 2016, and January 5, 2022, were enrolled in a prospective observational study. The primary outcomes were ICI-induced changes in HCV viremia (HCV inhibition and HCV reactivation) and safety of ICI.

We enrolled 52 consecutive patients with solid tumors treated with ICI. Most were men (41; 79%), White (31; 59%), without cirrhosis (34; 65%), and with HCV genotype 1 (40; 77%). Four patients (7.7%) experienced HCV inhibition while receiving ICI including 1 patient who developed undetectable viremia for 6 months in the absence of direct-acting antivirals (DAA). Two patients (4%) developed HCV reactivation, both while receiving immunosuppressive therapy for ICI-related toxic effects. Adverse events occurred in 36 patients (69%), and 39 of the 47 adverse events (83%) were grade 1-2. Grade 3-4 adverse events occurred in 8 patients (15%), and in all cases, they were related to ICI, not to HCV. No HCV-associated liver failure or death occurred.

Inhibition of HCV replication with virologic cure can develop in patients receiving ICI without DAA. HCV reactivation occurs primarily in patients receiving immunosuppressants for ICI-related toxic effects. ICI are safe in HCV-infected patients with solid tumors. Chronic HCV infection should not be considered a contraindication for ICI therapy.