Antiviral prophylaxis is recommended to prevent the reactivation of hepatitis B in patients who are:r
- HBsAg positive with haematological or solid tumour malignancy undergoing anti-cancer therapy
- HBsAg negative and anti-HBc positive and undergoing higher risk anti-cancer therapy
No antiviral prophylaxis is required for patients undergoing lower risk anti-cancer therapy who are HBsAg-negative and anti-HBc positive or who have no evidence of previous exposure to HBV.1 Immunisation against hepatitis B is recommended for patients who are HBV naive and BMT donors.r
Entecavir or tenofovir is recommended as first-line antiviral therapy and should be initiated as soon as possible relative to the start of anti-cancer therapy.rr
These third generation nucleotide analogues have low rates of viral resistance and studies have demonstrated superiority over lamivudine.r Although lamivudine has been shown to reduce the risk of reactivation by 79% or more when compared to placebo in patients undergoing chemotherapy,r it is not recommended due to the high rate of drug resistance than with other reverse transcriptase inhibitors.r
During antiviral prophylaxis, ALT and HBV DNA levels should be monitored every 3 months.rrr This may be increased to every 3 to 6 monthsr after the first 3 months.r
Testing for HBV DNA, ALT and HBsAg is recommended every 3 months for a minimum of 12 months after cessation of antiviral prophylaxis to monitor for an increase in HBV DNA levels.rr
Duration of prophylaxis
Recommendations on the duration of antiviral prophylaxis differ across international guidelines, ranging from 6 to 12 months after the cessation of chemotherapy, and for 12 to 24 months after the cessation of anti-CD20 monoclonal antibodies or BMT to reduce the risk of HBV reactivation which may occur after the withdrawal of antiviral therapy. rrrr
Therefore, the timing of cessation of antiviral therapy should be individualised and left to the discretion of the hepatologist. The duration of treatment is to be dependent on clinical judgement and on a case-by-case basis.
Flowchart for HBV antiviral prophylaxis in patients undergoing cancer therapy
Notes: “Lower risk” agents are all others not included in “higher risk”; implications for monitoring and duration of antivirals are discussed in the text. +Including rituximab, obinutuzumab, ocrelizumab, ofatumumab and ibrutinib; this is not an exhaustive list as new agents will be introduced and more evidence about the risk of HBV reactivation comes to light. *Lower level of evidence for risk of HBV reactivation in acute leukaemia and high-grade lymphoma therapy.
© Hepatitis B Management During Cancer Therapy Consensus Statement Group 2019