Phase 2 Data from Pfizer’s 20-Valent Pneumococcal Conjugate Vaccine (20vPnC) Candidate Shows Safety and Immunogenicity


 Pfizer presented data from a Phase 2 study of its 20-valent pneumococcal conjugate vaccine (20vPnC) candidate, PF-06482077, under development for the prevention of invasive disease and pneumonia caused by the 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 (ECCMID) in Amsterdam, Netherlands. PF-06482077 includes the 13 serotypes contained in Prevnar 13 plus seven additional serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F).

The randomized, active-controlled, double-blinded phase 2 trial enrolled 444 adult subjects age 60 to 64. Subjects received a single injection of 20vPnC or Prevnar 13 (Vaccination 1). One month later subjects receiving 20vPnC were given an injection of saline placebo, and subjects receiving Prevnar 13 were given 23-valent polysaccharide vaccine (Vaccination 2). Local reactions and systemic events were recorded for 10 and 7 days respectively after Vaccination 1 and data on adverse events (AEs) were collected for one month following each vaccination. Immunogenicity was assessed by measuring antibody associated with serotype-specific bacterial killing (opsonophagocytic activity ) 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.

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 (redness, swelling or pain) 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.

Based on the phase 2 data, three Phase 3 trials (NCT03828617, NCT03835975 and NCT03760146) evaluating 20vPnC in adults are underway. Combined, these three trials will enroll more than 6,000 adult subjects, including populations of vaccine-naïve adults and adults with prior pneumococcal vaccination.

About 20vPnC and Invasive Pneumococcal Disease

Pfizer’s 20vPnC candidate includes the 13 serotypes contained in Prevnar 13 plus seven additional serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F). The seven new serotypes included in 20vPnC are global causes of invasive pneumococcal disease, and are associated with high case-fatality rates, antibiotic resistance and/or meningitis. Together, the 20 serotypes included in 20vPnC are responsible for the majority of currently circulating pneumococcal disease in adults in the U.S. and globally.

The U.S. FDA granted Breakthrough Therapy Designation in September of 2018 for 20vPnC for the prevention of invasive disease and pneumonia in adults age 18 years and older. The FDA granted Fast Track designation in September of 2017 for use in adults aged 18 years and older and in May of 2017 for a pediatric designation.