Pfizer and BioNTech on Monday announced results from a Phase 2/3 trial showing a favorable safety profile and robust neutralizing antibody responses in children 5 to 11 years of age using a two-dose regimen of 10 micrograms administered 21 days apart, a smaller dose than the 30-microgram dose used for people 12 and older.
The antibody responses in the participants given 10-microgram doses were comparable to those recorded in a previous Pfizer-BioNTech study in people 16 to 25 years old immunized with 30-microgram doses. The 10-microgram dose was carefully selected as the preferred dose for safety, tolerability and immunogenicity in children 5 to 11 years of age. These are the first results from a pivotal trial of a COVID-19 vaccine in this age group.
“Over the past nine months, hundreds of millions of people ages 12 and older from around the world have received our COVID-19 vaccine. We are eager to extend the protection afforded by the vaccine to this younger population, subject to regulatory authorization, especially as we track the spread of the Delta variant and the substantial threat it poses to children,” said Albert Bourla, Pfizer chairman and CEO. “Since July, pediatric cases of COVID-19 have risen by about 240% in the U.S. – underscoring the public health need for vaccination. These trial results provide a strong foundation for seeking authorization of our vaccine for children 5 to 11 years old, and we plan to submit them to the FDA and other regulators with urgency.”
“We are pleased to be able to submit data to regulatory authorities for this group of school-aged children before the start of the winter season,” said Dr. Ugur Sahin, CEO and co-founder of BioNTech. “The safety profile and immunogenicity data in children aged 5 to 11 years vaccinated at a lower dose are consistent with those we have observed with our vaccine in other older populations at a higher dose.”
The data summarized from this Phase 2/3 study, which is enrolling children 6 months to 11 years of age, was for 2,268 participants who were 5 to 11 years of age and received a 10-microgram dose level in a two-dose regimen. In the trial, the SARS-CoV-2–neutralizing antibody geometric mean titer (GMT) was 1,197.6 (95% confidence interval [CI, 1106.1, 1296.6]), demonstrating strong immune response in this cohort of children one month after the second dose. This compares well to the GMT of 1146.5 (95% CI: 1045.5, 1257.2) from participants ages 16 to 25 years old, used as the control group for this analysis and who were administered a two-dose regimen of 30 micrograms. Further, the COVID-19 vaccine was well tolerated, with side effects generally comparable to those observed in participants 16 to 25 years of age.
Pfizer and BioNTech plan to share these data with the Food and Drug Administration, European Medicines Agency and other regulators as soon as possible. For the United States, the companies expect to include the data in a near-term submission for Emergency Use Authorization as they continue to accumulate the safety and efficacy data required to file for full FDA approval in this age group. A request to the EMA to update the EU Conditional Marketing Authorization is also planned. Topline readouts for the other two age cohorts from the trial – children 2-5 years of age and children 6 months to 2 years of age – are expected as soon as the fourth quarter of this year.
Pfizer and BioNTech plan to submit data from the full Phase 3 trial for scientific peer-reviewed publication.