Hepatotoxicity associated with PD-1 blockade antibodies in cancer patients co-infected with hepatitis B virus

The use of anti-programmed cell death-1 (PD-1) antibodies in treating malignancies is increasing; however, most registered clinical trials on anti-PD-1 antibodies exclude patients infected with hepatitis B virus (HBV). This retrospective study aimed to assess hepatotoxicity in cancer patients infected with HBV undergoing anti-PD1 antibody therapy and identify the associated risk factors. A total of 301 cancer patients positive for hepatitis B core antibodies (HbcAb) (negative or positive hepatitis B surface antigen [HBsAg]) who received PD-1 inhibitors were enrolled. The primary and secondary endpoints were the incidence rate of hepatotoxicity related to PD-1 inhibitor treatment, and risk factors associated with hepatic toxicity, respectively. Of the enrolled analyzed, 16.9% (n = 51) developed any grade and 4.7% (n = 14) developed grade 3-4 hepatotoxicity, respectively. Higher risk for any-grade hepatotoxicity development was associated with sero-positive HBsAg (OR = 6.30; P = 0.020), existence of liver involvement (OR = 2.10; P = 0.030), and detectable baseline HBV DNA levels (OR = 2.39; P = 0.012). Patients with prophylactic antiviral therapy decreased hazard for the incidence of grade 3-4 hepatotoxicity (OR = 0.10; P = 0.016). Our results suggested chronic (HBsAg-positive)/resolved (HBsAg-negative and HBcAb-positive) HBV-infected cancer patients are at an increased risk of hepatotoxicity following PD-1 inhibitor therapy. Cancer patients should be tested for HBsAg/HBcAb prior to the commencement of immune checkpoint inhibitor therapy. For patients with chronic/resolved HBV infection, ALT/AST and HBV DNA should be closely monitored during the whole immunotherapy period.