The purpose of this study is to learn about the safety and immune effects of a pneumococcal vaccine in adults. This vaccine can possibly provide protection against further pneumococcal disease. This study will happen in 4 stages: Stage 1 is seeking participants who are between 18 years to 49 years of age. The participants will receive 1 of 2 pneumococcal vaccine candidates (different formulations) or 20vPnC (Prevnar 20) as a single shot given into the upper arm muscle. Stage 2 will begin after participants have completed Stage 1, and a pneumococcal vaccine candidate has been decided. Stage 2 is seeking participants who are adults 50 years of age and older. The participants will receive the chosen pneumococcal vaccine candidate from Stage 1 or 20vPnC (Prevnar 20). The vaccines will be given as a single shot into the upper arm muscle. Stage 3 is seeking participants who are adults 50 years of age and older. The participants will receive the chosen pneumococcal vaccine candidate from Stage 1 or a licensed pneumococcal comparator vaccine. The vaccines will be given as a single shot into the upper arm muscle. Stage 4 is seeking participants who are adults 50 years of age and older. The participants will receive either one of three pneumococcal vaccine candidates or one of two licensed pneumococcal comparator vaccines. The vaccines will be given as a single shot into the upper arm muscle. Participants will take part in this study for about 6 months for Stage 1, Stage 3, and Stage 4 and 12 months for Stage 2. During this time participants will have from 2 to 4 clinic visits and 1 phone visit. At these clinic visits, participants will be asked if any side effects were experienced. The participants will also have to give blood samples during these clinic visits.
Phase 1 trials primarily test safety and dosing in a small number of participants (typically 20–100). Results do not yet speak to efficacy. FDA approval is typically many years away from this stage.
Phase 2 trials begin testing efficacy in a larger patient group (100–300). This is often where biotech binary events occur — positive Phase 2 data can significantly advance a company's pipeline narrative, while failures can be terminal for a program.
Enrollment is complete. The trial is in its follow-up or data collection phase — a readout may occur on or near the primary completion date.
Pfizer Inc (PFE) is the sponsoring company for this trial. BiotechSign currently grades this company F (33/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.