WHAT’S KNOWN?
Successful anti-PD-1 / PD-L1 immunotherapy requires an adequate number
of specific T cells in the tumor microenvironment. Similar to the tumor
microenvironment, the chronic viral infection is a strong
immunosuppression environment, leading to specific T cells exhausting,
in theory, it may influence the effect of ICI which has reversed the
role of T cell failure at the same time and undermine the balance
between the host immune system and virus control that has caused the
risk of liver damage. But there is not any consensus yet and appropriate
strategy of ICIs in this population needs in depth assessment. In the
existing published articles about safety and efficacy of ICIs in
patients with chronic viral infection and advanced-stage cancer, the
types of cancer involved are not comprehensive, with liver cancer and
melanoma accounting for the majority and NSCLC accounting for less than
five percent. In one retrospective study of PD-1 inhibitors for NSCLC
with special issues involving 32 HBV-infected patients, four of nine
patients experienced severe AST/ALT elevation (grade 3 or higher) were
HBV patients. And three patients developed viral reactivations or
flares, despite receiving anti-HBV therapy prior to the immunotherapy.