Positive top-line results from phase III study in 20-Valert Pneumococcal Conjugate Vaccine in infants in the European Union

The study had three coprimary outcomes, associated with immunogenicity responses one month after the second and third doses of a three-dose vaccination series given at approximately 2, 4, and 11-12 months of age of 20vPnC compared to Prevenar 13. For the non-inferiority (NI) co-primary objective of immunoglobulin G (IgG) geometric mean concentrations (GMCs) one month after Dose 3 at 11-12 months of age, 19 of the 20 serotypes met the NI criteria with only one serotype narrowly missing. For the NI co-primary objective of IgG GMCs one month after Dose 2, 16 of the 20 serotypes met NI. Finally, for the third NI co-primary objective of the percentage of participants with predefined serotype-specific IgG concentrations one month after Dose 2, nine of the 20 serotypes met the NI criteria. All 20 serotypes showed increased booster responses from post dose 2 to post dose 3 which are indicative of immunological memory and long-term protection. All 20 vaccine serotypes also showed strong functional antibody responses as measured by the opsonophagocytic assay (OPA) post-dose 2 and post dose 3 similar to Prevenar and Prevenar 13.

The totality of data is therefore directionally consistent with prior clinical experience with Prevenar and Prevenar 13 after 2 and 3 infant doses, both of which have demonstrated effectiveness in a three-dose schedule against the serotypes contained in the vaccine in post-licensure studies.

In summary, the totality of these positive 20vPnC data, combined with the experience with Prevenar 13 in this schedule, demonstrates that the 20vPnC candidate, if approved, is likely to help protect against all 20 vaccine serotypes in a three-dose vaccine series.