The Therapeutic Goods Administration (TGA) has issued a safety update regarding the potential for hepatitis B virus (HBV) reactivation in patients taking BCR-ABL tyrosine kinase inhibitors (TKI). This safety update follows a review of clinical trial and post-marketing data from the European Medicines Agency (EMA). Reports of HBV reactivation have included cases of acute hepatic failure and fulminant hepatitis leading to liver transplantation or death.
Affected TKIs available in Australia include imatinib, nilotinib, dasatinib, and ponatinib. These agents are indicated for specific blood cancers including chronic myeloid leukaemia (CML) and acute lymphoblastic leukaemia (ALL).
Reactivation of HBV is a well-known complication of immunosuppressive therapy in patients with chronic hepatitis B. While this is now considered a class effect of BCR-ABL TKIs, the mechanism of virus reactivation and frequency of occurrence is not known. Patients who are chronically infected are at a higher risk of reactivation than those with resolved infection. However, reactivation may still occur in patients with resolved infection due to the persistence of HBV covalently closed circular DNA (cccDNA) in hepatocytes and other tissues, which act as a reservoir for future infection.
The TGA recommends that all patients are tested for HBV before a BCR-ABL TKI is initiated. If a patient tests positive and TKI therapy is considered necessary, close monitoring for signs and symptoms of active HBV infection should occur throughout therapy and for several months after treatment discontinuation.
- Li GM, Yan SL, Chang CS, Tsai CY. Hepatitis B reactivation in chronic myeloid leukemia patients receiving tyrosine kinase inhibitor. World J Gastroenterol. 2013; 19(8): 1318-21.
- Pattullo V. Prevention of Hepatitis B reactivation in the setting of immunosuppression. Clin Mol Heaptol. 2016; 22(2): 219-37.
- Pharmacovigilance Risk Assessment Committee. PRAC recommendations on signals: adopted at the PRAC meeting of 8-11 February 2016. European Medicines Agency. 2016.