Pfizer announces presentation of data from Phase 2 study of 20vPnC candidate
Pfizer announced the presentation of data from a Phase 2 study of its 20-valent pneumococcal conjugate vaccine candidate, PF-06482077, being investigated for the prevention of invasive disease and pneumonia caused by Streptococcus pneumoniae serotypes contained in the vaccine in adults aged 18 years and older. The presentation was delivered at the 29th European Congress of Clinical Microbiology and Infectious Diseases in Amsterdam, Netherlands. Pfizer's 20vPnC candidate includes the 13 serotypes contained in Prevnar 13 plus seven additional serotypes. The Phase 2 study was a randomized, active-controlled, double-blinded trial that enrolled 444 adult subjects age 60-64. Subjects received a single injection of 20vPnC or Prevnar 13. One month later subjects receiving 20vPnC were given an injection of saline placebo, and subjects receiving Prevnar 13 were given 23-valent polysaccharide vaccine. Local reactions and systemic events were recorded for 10 and 7 days respectively after Vaccination 1 and data on adverse events were collected for one month following each vaccination. Immunogenicity was assessed by measuring antibody associated with serotype-specific bacterial killing prior to vaccination and one month after each vaccination. The study was designed to describe safety and immunogenicity data with 20vPnC in a population of older adults. Given the stage of the study there was no hypothesis testing and data were summarized. Of the 444 subjects enrolled, 443 received Vaccination 1 and 427 received Vaccination 2. Robust OPA responses were observed for all 20 vaccine serotypes in the 20vPnC group. The OPA geometric mean fold-rises from baseline ranged from 6.1 to 68.6 for the serotypes in common with Prevnar 13, and 9 to 112.2 for the seven additional serotypes not included in Prevnar 13. Injection site reactions and systemic event rates were similar after vaccination with 20vPnC or Prevnar 13, with severe injection site reactions or systemic events reported in less than one percent of 20vPnC recipients. No deaths or serious AEs considered related to vaccine were reported in the study. The overall safety profile of 20vPnC in this study was consistent with historical experience with Prevnar 13. The safety and immunogenicity findings from this Phase 2 study supported progression to Phase 3 clinical development for the adult indication which started in December 2018.