The objective of the present study was to assess the safety and efficacy of a therapeutic vaccine containing both HBsAg and HBcAg (NASVAC) in patients with chronic hepatitis B (CHB) three years after the end of treatment (EOT) as a follow-up of a phase III clinical trial. NASVAC was administered ten times by the nasal route and five times by subcutaneous injection. A total of 59 patients with CHB were enrolled. Adverse events were not seen in any of the patients. Out of the 59 CHB patients, 54 patients exhibited a reduction in HBV DNA, compared with their basal levels. Although all the patients had alanine transaminase (ALT) above the upper limit of normal (>42 IU/L) before the commencement of therapy, the levels of ALT were within the ULN level in 42 patients. No patient developed cirrhosis of the liver. The present study, showing the safety and efficacy of NASVAC 3 years after the EOT, is the first to report follow-up data of an immune therapeutic agent against CHB. NASVAC represents a unique drug against CHB that is safe, of finite duration, can be administered by the nasal route, is capable of reducing HBV DNA and normalizing ALT, and contains hepatic fibrosis.
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)