Sci B Vac Proven to Prevent Recurrence of Hepatitis B11th June...

Sci B Vac Proven to Prevent Recurrence of Hepatitis B

11th June 2007: Scigen Limited (ASX:SIE) announces that Sci B Vac, Scigen’s third
generation hepatitis B vaccine derived from mammalian cells (CHO), has been proven to
prevent recurrence of hepatitis B virus infection in patients receiving antiviral prohylaxis
(Lamivudine) after liver transplantation for chronic hepatitis B.

Anti-virals (Lamivudine) monoprophylaxis against hepatitis B virus (HBV) administered to
prevent reinfection after liver transplantation is associated with recurrence due to
escape mutants. Second generation recombinant HBV vaccine derived from yeast given
in combination with anti-viral is not effective in preventing such recurrence.

In an investigator sponsored study at the Center for the study of Liver Disease at the
University of Hong Kong and published in the American Journal of Transplantation
(2007:7:434-439) a combination of antiviral Lamivudin with Sci B Vac was administered
to 20 patients. The response rate was 88% in patients younger than 50 years old and
25% in older patients. At the completion of the study all patients remained free of
infection.

Hepatitis B Virus (HBV) is a major world health problem. There are over 300 Million
chronic carriers of infection and over 1 million deaths each year are attributed to hepatitis
B. The world market for the prevention and treatment of Hepatitis B virus is believed to
be over US$3 Billion dollars and growing.

About Sci B VacTM:
Sci B VacTM is a third generation recombinant hepatitis B Vaccine produced by Chinese
Hamster ovary cells. Sci B VacTM contains immunogenic regions of the three surface
proteins of HBV.

Sci B VacTM is a unique hepatitis B vaccine, which has repeatedly been shown to be
highly immunogenic and safe in neonates, children and adults alike.
Worldwide sales of hepatitis B vaccines are estimated to be US$1.2 billion.