When to start nucleoside analogues
Three antiviral oral nucleoside analogues are available as preferred therapies for chronic HBV: entecavir (Baraclude), tenofovir alafenamide (Vemlidy), and tenofovir disoproxil (Viread). All three provide high antiviral efficacy and low risk for resistance. The treatment goal is to prevent disease progression and HBV complications, including hepatocellular carcinoma, in individuals with active chronic hepatitis B.
The major liver disease medical societies differ only slightly on the criteria for starting treatment. Broadly, they recommend starting therapy in all patients with cirrhosis, as well as in patients without cirrhosis who have both a serum ALT level more than twice the upper limit of normal and elevated HBV DNA levels. The treatment threshold for HBV DNA levels is higher in patients who are HBeAg positive than it is for patients who are HBeAg negative; for example, the American Association for the Study of Liver Diseases recommends that an HbeAg-positive patient should have a HBV DNA titer greater than 20,000 IU/mL, which is a level 10 times higher than the group’s treatment threshold in HBeAg-negative patients. However, these thresholds are intended as guidance, not absolute rules, Dr. Terrault emphasized. Nearly 40% of patients don’t meet the dual ALT and HBV DNA thresholds, and serial monitoring of such patients for 6-12 months is recommended because they may be in transition.
The choice of nucleoside analogue is largely based on comorbidities. Any of the three preferred antivirals can be used when there are none. Tenofovir disoproxil is preferred in pregnancy because of its safety profile in that setting. In patients who are aged over 60 years or have bone disease or renal impairment, tenofovir alafenamide and entecavir are preferred. Entecavir should be avoided in favor of either form of tenofovir in patients who are HIV positive or have prior exposure to lamivudine.
Regarding treatment with these drugs, the recommendations target those whose liver disease is being driven by active HBV rather than fatty liver disease or some other cause. That’s the reason for the reserving treatment for patients with both high HBV DNA and high serum ALT.
“There’s definitely a camp that feels these are safe drugs, easy to use, and we should treat more people. I have to say I’m not hanging out in that camp. I still feel we should do targeted treatment, especially since there are many new drugs coming where we’re going to be able to offer cure to more people. So I feel like putting everybody on suppressive therapy isn’t the answer,” she said.
Dr. Terrault receives research grants from and/or serves as a consultant to numerous pharmaceutical companies.