Pfizer and BioNTech choose lead mRNA vaccine candidate against COVID-19 and commence pivotal phase II/III global study.

Pfizer Inc. and BioNTech SE announced the start of a global (except for China) Phase II/III safety and efficacy clinical study to evaluate a single nucleoside-modified messenger RNA (modRNA) candidate from their BNT162 mRNA-based vaccine program against SARS-CoV-2 .

After extensive review of preclinical and clinical data from Phase 1/II clinical trials, and in consultation with the FDA’s Center for Biologics Evaluation and Research (CBER) and other global regulators, Pfizer and BioNTech have chosen to advance their BNT162b2 vaccine candidate into the Phase II/III study at a 30 µg dose level in a 2 dose regimen. BNT162b2, which recently received FDA Fast Track designation, encodes an optimized SARS-CoV-2 full length spike glycoprotein (S), which is the target of virus neutralizing antibodies.

About the Phase II/III Study : Pfizer and BioNTech finalized the Phase II/III study protocol in response to feedback from global regulators, including the FDA and the German Paul-Ehrlich-Institut. The Phase II/III study is an event driven trial that is planned to enroll up to 30,000 participants between 18 and 85 years of age. The companies plan to enroll a diverse population, including participants in areas where there is significant expected SARS-CoV-2 transmission. The Phase II/III trial is designed as a 1:1 vaccine candidate to placebo, randomized, observer-blinded study to obtain safety, immune response, and efficacy data needed for regulatory review. The trial’s primary endpoints will be prevention of COVID-19 in those who have not been infected by SARS-CoV-2 prior to immunization, and prevention of COVID-19 regardless of whether participants have previously been infected by SARS-CoV-2. Secondary endpoints include prevention of severe COVID-19 in those groups.

The study also will explore prevention of infection by SARS-CoV-2, the virus that causes COVID-19. The primary efficacy analysis will be an event-driven analysis based on the number of participants with symptomatic COVID-19 disease. The trial design allows for interim analyses and unblinded reviews by an independent external Data Monitoring Committee. By the end of the trial, the Phase II/III study is expected to be active at approximately 120 clinical investigational sites around the world, including 39 states across the United States and countries including Argentina, Brazil, and Germany.

Investigator sites are selected based on factors including scientific expertise and capabilities, the epidemiology of the disease, and prior experience conducting clinical trials. For further information about this trial, visit using the number NCT04368728. Pfizer and BioNTech are committed to decreasing health disparities in underrepresented populations through the clinical trial process. To that end, many investigator sites are in diverse communities that have been disproportionately affected by COVID-19 so that individuals who have been most impacted have the opportunity to participate. The companies are also working together with investigator sites and advocacy partners to raise awareness about the importance of participation in this trial.

BNT162b2 remains under clinical study and is not currently approved for distribution anywhere in the world. If the Phase II/III trial is successful, Pfizer and BioNTech expect to be ready to seek Emergency Use Authorization or some form of regulatory approval as early as October 2020. If authorization or approval is obtained, the companies currently aim to supply globally up to 100 million doses by the end of 2020 and approximately 1.3 billion doses by the end of 2021..