Positive Phase III Results From Novel Two-Dose Vaccine Reported.(Brief Article)

2002 JAN 30 - (NewsRx.com & NewsRx.net) -- Rhein Biotech, N.V., and Corixa Corporation announced positive preliminary efficacy results of a Phase III clinical trial with a novel two-dose hepatitis B vaccine.

The new vaccine is based on Rhein Biotech's Hansenula polymorpha yeast based recombinant hepatitis B antigen (HBsAg), the active ingredient of commercially approved hepatitis B vaccines (Hepavax-Gene, AgB, Biovac B), and Corixa's RC-529 synthetic adjuvant.

The hepatitis B vaccines currently commercially available generally need three injections for full protection. Results of the primary efficacy analyses showed that there were significantly more individuals seroprotected after two immunizations with Rhein Biotech hepatitis B vaccine plus RC-529 than with two immunization of the three dose Rhein Biotech vaccine alone (95.5% vs. 82.1%, p=0.001). This shows that the Rhein Biotech vaccine with RC-529 allows reduction from the standard three doses to two doses. Preliminary efficacy results were presented by Corixa and Rhein Biotech at the 2002 World Health Organization's "Third Meeting on Novel Adjuvants Currently in/close to Human Clinical Testing" which was held in Annecy, France.

The study was designed to compare the efficacy and safety of vaccination with Rhein Biotech vaccine plus Corixa's RC-529 adjuvant to vaccination with the standard Rhein Biotech vaccine alone in healthy adults who were not immune to HBV. Healthy adults were randomized to one of two treatment arms and will have received three intramuscular injections of Rhein Biotech Hepatitis B vaccine plus RC-529 or Rhein Biotech vaccine alone on days 0, 30, and 180. The primary objective was to evaluate the number of individuals who were seroprotected at day 90 following only two vaccinations with Rhein Biotech vaccine plus RC-529 compared with two vaccinations of Rhein Biotech vaccine alone.

Secondary efficacy endpoints were: the number (percentage) of individuals achieving seroprotection at day 30 and day 60; the number (percentage) of patients achieving seroconversion (defined as an anti-HBsAg titer of = 1 MIU/mL) at day 30, day 60, or day 90 visits; and the anti-HBsAg titer (antibody levels) at days 30, 60, and 90.

A total of 272 vaccinated patients were evaluated for ...