Pfizer announces positive top-line results from phase III Lot Consistency Study of 20-Valent pneumococcal conjugate vaccine in pneumococcal vaccine-naive adults 18 through 49 years of age

Pfizer Inc. announced top-line results from a second Phase 111 study (NCT03828617), which described the safety and evaluated the consistency of immune responses elicited across three different lots of its 20-valent pneumococcal polysaccharide conjugate vaccine (20vPnC) candidate in adults 18 through 49 years of age not previously vaccinated against pneumococcal disease.

Responses elicited by 20vPnC for all 20 serotypes were equivalent across all three lots, meeting the primary immunogenicity objective of the study. In this study the 20vPnC safety profile was similar to the Prevnar 13 (pneumococcal 13-valent Conjugate Vaccine [Diphtheria CRM197 Protein]) control group. This clinical lot consistency study is expected to satisfy licensure requirements for manufacturing consistency by the FDA, and other countries’ regulatory agencies.

Pfizer will seek to present and publish outcomes from this clinical trial at a future date once safety and immunogenicity data have been fully analyzed.

This press release refers to NCT03828617: Phase III randomized, double-blind trial enrolled 1,700 adults aged 18 through 49 years with no history of pneumococcal vaccination. The study was designed to describe the safety and evaluate consistency of immune response elicited across three different lots of 20vPnC. The 20vPnC lots were three unique drug product lots. A 13vPnC arm was included in the study as a control group for safety assessments. More on the study can be found on under the identifier NCT03828617. Additional trials include: NCT03760146: Phase III randomized, double-blind trial comparing immune responses in patients ?60 years old after 20vPnC administration to responses in a control group receiving 13vPnC or PPSV23. The study also evaluated immune responses of 20vPnC in adults 18 to 59 years (secondary endpoints) and described the safety profile of 20vPnC in all adults ?18 years old (primary endpoint). Additional information about the study can be found at under the identifier NCT03760146.