Pfizer and BioNTech Commence Global Clinical Trial to Evaluate COVID-19 Vaccine in Pregnant Women

Pfizer Inc. and BioNTech SE announced that the first participants have been dosed in a global Phase 2/3 study to further evaluate the safety, tolerability, and immunogenicity of the Pfizer-BioNTech COVID-19 vaccine(BNT162b2) in preventing COVID-19 in healthy pregnant women 18 years of age and older.

“We are proud to start this study in pregnant women and continue to gather the evidence on safety and efficacy to potentially support the use of the vaccine by important subpopulations,” said William Gruber M.D., Senior Vice President of Vaccine Clinical Research and Development, Pfizer. “Pregnant women have an increased risk of complications and developing severe COVID-19, which is why it is critical that we develop a vaccine that is safe and effective for this population. We are deeply thankful to the volunteers who are enrolling in the trial, and site investigators who are leading this work.”

“Enabling broad access to our highly effective COVID-19 vaccine is an important goal for us. Now that we are seeing successful initial implementation of vaccine campaigns with BNT162b2 across the globe, it is time to take the next step and extend our clinical program to other vulnerable populations, such as pregnant women, to potentially protect both them and future generations,” said Özlem Türeci, M.D., Chief Medical Officer of BioNTech.

The Phase 2/3 trial is designed as a randomized, placebo-controlled, observer-blind study in approximately 4,000 healthy pregnant women 18 years of age or older vaccinated during 24 to 34 weeks of gestation. The study will evaluate the safety, tolerability, and immunogenicity of two doses of BNT162b2 or placebo administered 21 days apart. Each woman will participate in the study for approximately 7 to 10 months, depending on whether she was randomized to receive the vaccine or placebo. The study will assess safety in infants of vaccinated pregnant women and the transfer of potentially protective antibody to their infants. Infants will be monitored through approximately six months of age. As established in the study protocol, after a participant’s infant is born, maternal trial participants will be unblinded and those who were in the placebo group will receive the vaccine.

Prior to conducting their COVID-19 vaccine clinical trial in pregnant women, Pfizer and BioNTech completed a developmental and reproductive toxicity (DART) study with BNT162b2, which was required by the regulatory authorities before starting the study in pregnant women. Those studies showed no evidence of fertility or reproductive toxicity in animals.

Pfizer is leveraging its expertise in conducting clinical trials in pregnant women, informed by the experience with its ongoing trials for vaccine candidates against Respiratory Syncytial Virus (Phase 3), and Invasive Group B Streptococcus Infection (Phase 2).

Pfizer and BioNTech expect to start additional studies in children between the ages of 5 and 11 over the next couple of months, and in children younger than 5 later in 2021. Safety and efficacy in subjects 12 to 15 years of age are already being evaluated in the global Phase 3 study (C4591001) and the relevant data are planned to be submitted to the regulatory authorities in the second quarter of 2021. The Companies are also planning studies to further evaluate the vaccine in people with compromised immune systems.

The Pfizer-BioNTech COVID-19 Vaccine has not been approved or licensed by the U.S. Food and Drug Administration (FDA), but has been authorized for emergency use by FDA under an Emergency Use Authorization (EUA) to prevent Coronavirus Disease 2019 (COVID-19) for use in individuals 16 years of age and older. The emergency use of this product is only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of the medical product under Section 564 (b) (1) of the FD&C Act unless the declaration is terminated or authorization revoked sooner.

The vaccine, which is based on BioNTech proprietary mRNA technology, was developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorizations Holder in the European Union, and the holder of emergency use authorizations or equivalent in the United States, United Kingdom, Canada and other countries in advance of a planned application for full marketing authorizations in these countries.