Acambis' JE vacc meets Ph III efficacy endpoint

UK-based vaccines developer Acambis says that its single-dose Japanese encephalitis vaccine ChimeriVax has met the primary immunogenecity endpoint in a Phase III trial. The firm added that the product had in fact exceeded expectations, with almost all of those who received it going on to achieve neutralizing levels of antibody seroconversion within a 30-day period.

The program, which was a randomized, double-blind assessment, recruited 820 healthy adult participants who were then randomized to receive either ChimeriVax or Sanofi Pasteur's three-dose JE-VAX product. The aim of the assessment was to demonstrate non-inferiority to the Sanofi vaccine.

The results showed that 99.1% of those treated with the Acambis vaccine reached the predefined seroconversion goals, compared with 74.8% in the JE-Vax arm. The firm also reported that 93.6% of those who received Chimerivax achieved maximum seroconversion 14 days after administration. Additionally, the number of adverse events observed during the program's 60-day observation period was slightly lower for Chimerivax than for JE-Vax.