In treatment-naïve patients with chronic hepatitis B virus (HBV) infection, a therapeutic vaccine candidate (NASVAC) more effectively reduced viral load compared with pegylated interferon (Peg-IFN), according to study results published in PLoS ONE.
NASVAC is comprised of 100 μg of hepatitis B surface antigen (HBsAg) and 100 μg of hepatitis B core antigen (HBsAg).
The study included treatment-naïve participants with chronic HBV (n=160) who were randomly assigned to receive either NASVAC (n=80) or Peg-FN (n=80). NASVAC was administered in two 5-dose cycles. In the peg-FN group, participants received weekly doses of 180 μg Peg-IFN alfa 2 b administered via subcutaneous injection for 48 weeks. The primary outcome was the percentage of participants showing reduction in viral load under the limit of detection (250 copies/mL) 24 weeks after treatment completion.
After 24 weeks of post-treatment follow-up, the researchers found that significantly more participants in the NASVAC group had sustained control of HBV DNA (57.7%) compared with participants in the Peg-IFN group (35.05%, P <.01).
The researchers detected NASVAC-induced increases in alanine aminotransferases in 85% of participants after 5 nasal vaccinations; this effect was only seen in 30% of participants receiving Peg-IFN.
At the end of treatment, the antiviral effect was similar in both the NASVAC and the Peg-IFN groups (59.0% and 62.5%, respectively; P>.05).
Participants in the NASVAC group were more likely to experience clearance of hepatitis B e antigen (5 out of 14; 35.7%) compared with participants in the Peg-IFN group (3 out of 16; 18.7%).
The results also indicated that participants in the NASVAC group had a lower rate of progression to cirrhosis compared with participants in the Peg-IFN group.
Neither treatment group reported any serious adverse events.
“This study indicates that the impact of therapeutic vaccination in the treatment of chronic infectious diseases will depend on the capacity of designing the adequate antigens and adjuvant strategies as well as the selection of the most suitable immunization route and candidate recipients,” the researchers wrote.
Mahtab MA, Akbar SMF, Aguilar JC, et al. Treatment of chronic hepatitis B naïve patients with a therapeutic vaccine containing HBs and HBc antigens (a randomized, open and treatment controlled phase III clinical trial) [published online August 22, 2018]. PLoS One. doi:10.1371/journal.pone.0201236