Clinical Trial: Study Comparing a 13-valent Pneumococcal Conjugate Vaccine With 23-valent Pneumococcal Polysaccharide Vaccine in Adults

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Phase 3, Randomized, Active-Controlled, Modified Double-blind Trial Evaluating the Safety, Tolerability, and Immunogenicity of a 13-valent Pneumococcal Conjugate Vaccine (13vPnC) Compared to a 23-va

Brief Summary: This study will assess the safety, tolerability and immune response of 13-valent pneumococcal conjugate vaccine (13vPnC) compared with 23-valent Pneumococcal Polysaccharide Vaccine (23vPS). Although the study started with only 1 population, amendments to the original protocol will now reflect three participant populations. Three age cohorts will be enrolled. The first cohort (age 60-64) will be blinded. Cohort 2 (age 50-59) and cohort 3 (age 18-49) are open label. Subjects in cohorts 1 and 2 will receive 2 vaccinations 3-4 years apart. Subjects in cohort 3 will receive 1 vaccination. All participants should be naïve of 23vPS. Comparisons of immune responses from the different cohorts will be done.

Detailed Summary:
Sponsor: Pfizer

Current Primary Outcome:

  • Serotype-specific Opsonophagocytic Activity (OPA) Geometric Mean Titers (GMTs) 1 Month After Vaccination 1 [ Time Frame: One month after vaccination 1 ]
    Serotype-specific OPA GMTs for the 13 pneumococcal common serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) were determined in the blood samples of all the participants using microcolony OPA (mcOPA) assay. CIs for GMT are back transformations of a CI based on the Student t distribution for the mean logarithm of the titers.
  • Percentage of Participants Achieving At Least a 4-fold Rise in OPA Titer for Serotype 6A 1 Month After Vaccination 1 in Cohort 1 [ Time Frame: One month after vaccination 1 ]
    For serotype 6A the percentage of participants achieving at least a 4-fold rise on the serotype-specific antibody titer from pre-vaccination to 1 month post-vaccination was computed along with exact, 2-sided 95% confidence interval for the proportion.
  • Serotype-specific Opsonophagocytic Activity (OPA) Geometric Mean Titers (GMTs) 1 Month After Vaccination for 12 Common Serotypes in 13vPnC/23vPS Group Relative to 23vPS Group and 23vPS/23vPS Group [ Time Frame: One month after vaccination 1 and One month after vaccination 2/Year 3 to 4 ]
    Serotype-specific OPA GMTs for the 12 pneumococcal common serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) were determined in the blood samples of all the participants using mcOPA assay. CIs for GMT are back transformations of a CI based on the Student t distribution for the mean logarithm of the titers.


Original Primary Outcome: To demonstrate that the immune responses to the 13vPnC serotypes induced by the 13vPnC vaccine are noninferior to the common serotypes immune responses induced by the 23vPS vaccine.

Current Secondary Outcome:

  • Percentage of Participants Achieving OPA Titers With at Least Lower Limit of Quantification (LLOQ) 1 Month After Vaccination 1 [ Time Frame: One month after vaccination 1 ]
    Percentage of participants achieving OPA GMTs with at least LLOQ for 13 pneumococcal serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F) determined in blood samples of all participants using mcOPA assay. Exact 2-sided CI based on observed proportion of participants. LLOQ for each serotype: 1=1:18, 3=1:12, 4=1:21, 5=1:29, 6A=1:37, 6B=1:43, 7F=1:210, 9V=1:345, 14=1:35, 18C=1:31, 19A=1:18, 19F=1:48, 23F=1:13.
  • Pneumococcal Opsonophagocytic Activity (OPA) Geometric Mean Fold Rises (GMFRs) for the 13 Serotypes From Prevaccination 1 to 1 Month After Vaccination 2 in Cohort 1 and Cohort 2 [ Time Frame: Prevaccination 1 to 1 month after vaccination 2/Year 3 to 4 ]
    Geometric mean fold rises (GMFRs) for the 13 serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) from prevaccination to 1 month postvaccination were computed using the logarithmically transformed assay results. CI for the GMFRs are back transformations of a CI based on the Student t distribution for the logarithmically transformed assay results.
  • Serotype-specific Pneumococcal Immunoglobulin G (IgG) Geometric Mean Concentration (GMC) for 12 Common Serotypes in 13vPnC/23vPS Group Relative to 23vPS and 23vPS/23vPS Groups in Cohort 1; and in 13vPnC/13vPnC Group in Cohort 2, 1 Month After Vaccination [ Time Frame: One month after vaccination 1 and One month after vaccination 2/Year 3 to 4 ]
    Antibody geometric mean concentration (GMC) as measured by microgram/milliliter (mcg/mL) for 12 common pneumococcal serotypes (1, 3, 4, 5, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) are presented. GMC and corresponding 2-sided 95% confidence intervals (CI) were evaluated. Geometric means (GMs) were calculated using all participants with available data for the specified blood draw.


Original Secondary Outcome: Safety evaluation

Information By: Pfizer

Dates:
Date Received: January 25, 2007
Date Started: March 2007
Date Completion:
Last Updated: August 1, 2012
Last Verified: August 2012