Tenofovir disoproxil fumarate for prevention of mother-to-child transmission of hepatitis B virus: A systematic review and meta-analysis of randomised control trials

Safety of Tenofovir Disoproxil Fumarate Among Breastfeeding Infants of Patients With Chronic Hepatitis B: A Systematic Review

An integral component to achieving worldwide chronic hepatitis B (CHB) elimination is addressing vertical transmission. Guidelines differ in their recommendations for breastfeeding while on tenofovir disoproxil fumarate (TDF). To conduct a systematic review of published studies analysing the concentration of tenofovir (TFV) in the breast milk of mothers receiving TDF and determining infant exposure from breastfeeding. We conducted a systematic literature search of studies evaluating infant safety from the breast milk of breastfeeding mothers receiving TDF for any indication that reported a TFV breast milk concentration. Daily infant exposure was used to calculate the relative dose of TFV in infants. Other pertinent information collected was the concentration of TFV in maternal and infant plasma, the duration of therapy of TDF and the indication for TDF. We identified 10 studies including 443 patients-266 of whom were mothers, and the remaining were infants-that reported the TFV concentration of breast milk in breastfeeding mothers receiving TDF. A total of 654 breast milk samples were included. The mean TFV concentration from all the studies that reported a median concentration of TFV was 4.8 ng/mL (95% CI [3.8, 5.8]). The mean infant exposure of TFV from breast milk was 0.56 μg/kg/day (95% CI [0.44, 0.68]). The mean relative dose was determined to be 0.01% of the weight-based recommended infant dose. Infant plasma levels of TFV were also collected. This was undetectable in a majority of the studies that reported it. Based on the negligible infant exposure of TFV while breastfeeding, from a pharmacologic and toxicity standpoint, maternal dosing of TDF appears safe for breastfeeding infants.

Efficacy and safety of therapeutic vaccines for the treatment of chronic hepatitis B: A systematic review and meta-analysis of randomized controlled trials update

BACKGROUND

Most people diagnosed with chronic hepatitis B (CHB) need treatment to help reduce the risk of liver disease and limit disease transmission. Therapeutic vaccine (TV) candidates have been under study for their clinical effects on inducing HBV-specific host immune responses. This review aimed to systematically synthesize updated evidence on the efficacy and safety of TVs in patients with CHB.

METHODS

This systematic review was performed by searching different databases from January to February 2021. Completed randomized controlled trials that reported TVs' efficacy and/or safety for treating CHB compared with the standard of care (SOC) or placebo were included. Efficacy and safety estimates were reported as the logarithm of the odds ratio and risk differences, respectively. I2 > 50% was considered significant heterogeneity. Significant publication bias was considered when Egger's test P value < .10. The risk of bias was assessed using the Cochrane Risk of Bias tool. The GRADE methodology was used to assess the certainty of the evidence for each outcome.

RESULTS

Twenty-four articles with 2889 pooled samples were included. TVs made a significant difference in hepatitis B envelope antigen (HBeAg) SC (log OR = 0.76, P = .01) and (log OR = 0.40, P = .03) compared to placebo and combination therapy, respectively. HBeAg SC was significantly affected by TVs at the end of follow up (log OR = 0.49, P = .01), with significant HBsAg mean difference (MD = -0.62, P = .00). At the end of treatment, the TVs had no significant effect on HBV DNA negativity over the SOC (log OR = 0.62, P = .09) or placebo (log OR = -0.07, P = .91). TVs do not significantly affect the risk of serious adverse events (RD 0.02, 95% CI 0.00-0.04).

CONCLUSION

In patients with CHB, TVs had significant effects on HBeAg SC compared to the SOC or placebo. There was no significant difference between serious adverse events. TVs are promising treatment strategy to overcome CHB.

Effectiveness and Safety of Tenofovir Alafenamide Fumarate in the Prevention of Perinatal Hepatitis B Transmission: A Meta-Analysis

AIM

This study aimed to assess the effectiveness and safety of tenofovir alafenamide fumarate (TAF) in the prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV).

METHODS

We performed a meta-analysis of studies from the Cochrane Library, PubMed, ClinicalTrials.gov, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI), China Medical Information Network, and Wanfang databases. The databases were searched from inception to January 7, 2023, for cohort studies and randomized controlled trials (RCTs) comparing the use of TAF antivirals to other antivirals during pregnancy. We combined the data by means of a random-effect DerSimonian-Laird model and risk ratios (RRs) or a random-effect inverse variance model and standardized mean differences (SMDs) to determine the influence on mothers and infants. Our primary outcomes were infant weight, height, head size, birth defects, and Apgar scores. Additionally, we assessed whether newborns tested positive for hepatitis B surface antigen (HBsAg) at birth and at six months of age. The secondary outcomes of our investigation were alterations in levels of HBV deoxyribonucleic acid (DNA), alanine aminotransferase (ALT), total bilirubin (TBIL), blood creatinine, and urine β2-microglobulin (β2-M) in mothers.

RESULTS

An extensive literature search identified 216 relevant publications; three cohort studies and two RCTs were included in this study. A total of 341 mothers were treated with TAF, and 342 were treated with other antiviral agents. TAF was as effective as other antiviral medications at lowering HBV MTCT rates at birth and at 6 months of age and ALT, TBIL, and HBV DNA levels. Moreover, compared with other antiviral drugs, TAF did not affect infant weight, height, head size, Apgar scores, and birth defects or maternal blood creatinine or β2-M levels.

CONCLUSIONS

TAF antiviral therapy during pregnancy was found to be safe for both mothers and fetuses.

Hepatitis B: Who should be treated?-managing patients with chronic hepatitis B during the immune-tolerant and immunoactive phases

New hepatitis B virus (HBV) infections are decreasing owing to improved antiviral therapy and increased HBV vaccination worldwide; however, the number of HBV infections remains a major cause of liver carcinogenesis. HBV triggers cytotoxic immunity to eliminate HBV-infected cells. Therefore, the HBV pathophysiology changes in persistently infected individuals depending on host immune responses and HBV DNA proliferation state. To prevent liver cirrhosis and carcinogenesis caused by HBV, it is important to treat HBV infection at an early stage. Active treatment is recommended for the immunoactive hepatitis B surface-antigen-positive and -negative phase, but not during the immune-inactive phase or immune-tolerant phase; instead, follow-up is recommended. However, these patients should be monitored through regular blood tests to accurately diagnose the immune-inactive or -tolerant phases. The treatment regimen should be determined based on the age, sex, family history of liver cancer, and liver fibrosis status of patients. Early treatment is often recommended due to various problems during the immune-tolerant phase. This review compares the four major international practice guidelines, including those from the Japanese Society of Hepatology, and discusses strategies for chronic hepatitis B treatment during the immune-tolerant, immune-inactive, and resolved phases. Finally, recommended hepatitis B antiviral therapy and follow-up protocols are discussed.