Experimental Drugs for HBV Infection3

liver411

HBV/MF59



A novel therapeutic vaccine for chronic hepatitis B looks promising. Teresa Wright, MD, from the University of California at San Francisco presented an interesting report about a new vaccine to help treat chronic hepatitis B. It is called "HBV/MF59." It combines the HBV (hepatitis B virus) "re S2 and S" antigen proteins with an "MF59 adjuvant" (vehicle to help boost immune responses). It is suspended in an oil-in-water emulsion that reportedly enhances the immune stimulating activity of the protein antigens. The current FDA-approved prophylactic (preventive) vaccines to prevent hepatitis B use an alum adjuvant that has less immune stimulating activity.



A series of four injections were given at baseline and one, two, and six months later to 13 persons with chronic hepatitis B. Then they were followed for an additional six months. The results showed that among the eight patients who were "e" antigen positive, three had significant reductions in "e" antigen, appearance of "e" antibody, with marked reductions in HBV DNA viral load and reductions or normalization of their ALT liver enzyme. These beneficial changes were preceded by a hepatitis "flare," (transient increase in liver enzymes, sometimes with hepatitis symptoms) that may occur before an improvement in immune control of HBV. Antibodies to hepatitis surface antigen developed in 11 of the 13 participants, but none lost surface antigen. The most common side effect was rash at the injection site. Dr. Wright concluded that a randomized, controlled clinical trial would be indicated, based on these findings. Chiron is developing the new vaccine.







References





Wright T and others. Phase I study of a potent adjuvanted hepatitis B vaccine (HBV/MF59) for therapy of chronic hepatitis B. Abstract and oral presentation 1042 at the 50th Annual Meeting of the American Association for the Study of Liver Diseases. Dallas, Texas; November 5-9, 1999. Hepatology 30(4) Supp2, 421A.