European Medicines Agency Assessment Report November 2012 Bexsero® Meningitis B produced in E.Coli by recombinant DNA vaccine ( Meningococcal group B Vaccine (rDNA, component, adsorbed)) 2.5. Clinical efficacy --------- No efficacy studies were performed during the clinical development of Bexsero. For practical reasons, meningococcal efficacy trials in non-epidemic settings are not considered feasible. Thus, the licensure application is based on a serological surrogate marker for protection, serum bactericidal antibody (SBA). The SBA measures the level of antibodies that recognize bacterial surface antigens and are capable of directing complement-mediated bacterial lysis, the main mechanism by which N. meningitidis serogroup B strains are killed after natural infection. Persistence of Immune Responses (Results at Six Months After the Third Vaccination) ------ When comparing the proportions of subjects with bactericidal titers ≥ 1:4 at 6 months after the third vaccination with those at 1 month after the third vaccination a decrease in the proportion of subjects with bactericidal titers ≥ 4 was observed for a majority of the strains. However, for some strains, unchanged or increased proportions of subjects with bactericidal titers ≥ 1:4 were observed at 6 months after the third vaccination. Similar trends were observed for the other measures of immunogenicity when comparing the results from 6 months after the third vaccination with the results from 1 month after the third vaccination. The objective to explore the in vitro assay for evaluation of a vaccine-specific memory B cell induced by Novartis meningococcal B recombinant vaccine +/- OMV was assessed by cell-mediated immunity (CMI). Only a small subset of subjects was identified for the evaluation of the response, which was not expected to give a reliable estimate of B cell maturation. Ad hoc blood samples were collected in a subset of 10 subjects per vaccination group at baseline and 6 months after the third dose. Memory B cells were measured for antigens 287-953, 936-741 and 961C. The results indicate an increased frequency of B cells after 6 months compared to baseline for antigens 936-741 and 961C, but the sample size is very small, and the variation appears to be large. Adjuvant: ----------- The drug substances are adsorbed on aluminium hydroxide (Al(OH)3) as a suspension for injection. The Al(OH)3 concentration in Bexsero is 1.5 mg/ dose which corresponds to 0.5 mg of elemental aluminium per vaccine dose.
Posted on: Tue, 25 Mar 2014 18:59:35 +0000
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