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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

DISCUSSION

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.

919. Rates of False-Positive Hepatitis B Surface Antigen Is Low in Cancer Patients

Background

Accurate interpretation of hepatitis B virus (HBV) laboratory testing is paramount in avoiding inaccurate diagnosis and incorrect management that could lead to unnecessary and overtreatment. This is particularly relevant in patients with cancer where universal testing is recommended in order to avoid HBV reactivation. Hepatitis B surface antigen testing (HBsAg) positivity indicates chronic or acute HBV infection. The rates and outcomes of a false-positive HBsAg have not been established for patients with cancer.

Methods

Three hundred and ninety-seven patients with any type of cancer and positive HBsAg seen at MD Anderson Cancer Center from January 2016 – January 2021 were retrospectively reviewed in this study approved by the institutional review board. Cases of false-positive HBsAg were defined as those patients with a positive HBsAg but negative HBsAg quantitative, negative HBV core antibody (total Ig), and undetectable HBV DNA within 30 days of positive HBsAg testing. Serum samples from patients were tested for HBsAg using Vitros Enhanced Chemiluminescent Immunoassay (Ortho-Clinical Diagnostics, Raritan, NJ, USA). Data collection includes demographics, past medical history, underlying cancer and its stage, prior cancer treatment, risk factors for HBV, co-infections (hepatitis C, HIV), symptoms, liver function tests, anti-HBV treatment, and interruptions on cancer treatment.

Results

Out of 397 patients with a positive HBsAg, 33 were excluded as they did not meet the diagnostic criteria or have insufficient HBV data. Of them, 3 cases (0.8%) were identified as false positive HBsAg. All 3 patients were female, white, and had progressive malignancy (Table 1). No prior history of liver disease or liver function abnormalities were noted with these 3 patients. Initially, antiviral treatment was started on 1 patient which was discontinued shortly after confirmation of false-positive HBsAg. All 3 patients had additional workup and evaluation by an HBV specialist. In 2 patients, cancer treatment was canceled or delayed.

Conclusion

Although uncommon, cancer patients with false-positive HBsAg need further workup to avoid overtreatment and unnecessary interruptions in cancer care

Disclosures

Jessica P. Hwang, MD, MPH , Merck (Grant/Research Support)