AASLD 2013: New Treatment for Hepatitis B—A Therapeutic Vaccine That May Finally Work



— Christine M. Kukka, Project Manager, HBV Advocate

For years researchers have tried unsuccessfully to develop a "therapeutic" vaccine using different antigens from the hepatitis B virus (HBV) in hopes of finding one that would kickstart the immune system into fighting and eradicating the infection.

Japanese researchers may have finally found one. In a Phase III clinical trial, they treated 160 hepatitis B patients with either pegylated interferon (a drug currently used to strengthen the immune system) or the experimental vaccine containing both the hepatitis B surface antigen (HBsAg) and the core antigen to see if together they would trigger the immune system to fight the infection. Current hepatitis B vaccines used to protect uninfected people contain only the surface antigen to spur production of surface antibodies.

In the study, 75 people received five courses of the experimental two-antigen immunization, which was administered by both injection and a nasal spray over a 10-week period. In the interferon-treated control group, 76 people were treated for 48 weeks, then both groups were followed for 24 weeks after the treatment and immunizations ended.

Researchers reported that 75 (61%) of patients receiving the vaccine achieved undetectable viral load (HBV DNA ), and they remained undetectable during the 24-week follow-up period. Seventy-six patients (67%) receiving interferon achieved undetectable viral load, however, only 39% remained undetectable 24 weeks after treatment ended.

There were no dangerous rises in alanine transferase (ALT) levels, signaling liver damage, in the vaccine-treated group over the study period. "This study inspired optimism that ongoing protocols of immune therapy against chronic hepatitis B may be improved by altering (the) nature of antigens and route of administration," researchers wrote.

CONTROL ID 1734018. A phase III clinical trial with a therapeutic vaccine containing both HBsAg and HBcAg administered via both mucosal and parenteral routes in patients with chronic hepatitis B. (Abstract #923)

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