Pfizer, BioNTech Initiate Phase 2 Study of Enhanced COVID-19 mRNA-Based Vaccine

Pfizer and BioNTech have initiated an active-controlled, observer-blind, phase 2, randomized study to evaluate the immune response, safety, and tolerability of an enhanced COVID-19 mRNA-based vaccine candidate at a 30-µg dose level, Pfizer said in a statement.

The enhanced vaccine, BNT162b5, will consist of RNAs encoding enhanced prefusion spike proteins for the SARS-CoV-2 ancestral strain and an Omicron variant. The enhanced spike protein encoded from the mRNAs in the vaccine has been modified with the aim of increasing the breadth and magnitude of the immune response that could better protect against COVID-19.

This is the first of multiple vaccine candidates with an enhanced design that the companies plan to evaluate, according to the statement.

The initiative is part of a long-term COVID-19 vaccine strategy aimed at generating broader, longer-lasting, and more robust immune responses against SARS-CoV-2 infections and associated COVID-19.

BNT162b5 will be evaluated in a US-based study, which will enroll approximately 200 individuals between aged 18 and 55 years who received 1 booster dose of a US-authorized COVID-19 vaccine at least 90 days prior to the study.

Individuals in the study will be separated into 2 groups by the number of months since their last dose of COVID-19 vaccine received prior to entering the study: 3 to 6 months or more than 6 months.

This study will not include a placebo, according to the statement.

The Pfizer-BioNTech COVID-19 vaccine, BNT162b2, which is based on BioNTech’s mRNA technology, was developed by both companies, and BioNTech is the marketing authorization holder in Canada, the European Union, the United Kingdom, the United States, and other counties.

BioNTech is also the holder of the emergency use authorization (EUA) or equivalents in the United States, along with Pfizer, and other countries. The submissions for regulatory approvals in those countries are planned.

The Pfizer-BioNTech COVID-19 vaccine is FDA-authorized under EUA for active immunization to prevent COVID-19 caused by SARS-CoV-2 in individuals aged 6 months and older.

It is authorized to provide a 3-dose primary series to individuals aged 6 months through 4 years, a 2-dose primary series to individuals aged 5 years and older, and a third primary series dose to individuals aged 5 years and older who are immunocompromised.

As for a booster series, it is authorized as a single booster dose to individuals aged 5 to 11 years who completed a primary series with the same vaccine.

It is also authorized as a first booster dose to individuals aged 12 years and older who have completed a primary series with the same vaccine, or Comirnaty vaccine, as well as a booster dose to individuals aged 28 years and older who have competed a primary vaccination with another authorized or approved COVID-19 vaccine.

A second booster dose is authorized for individuals aged 50 years and older who have received a first booster dose of any approved or authorized COVID-19 vaccine and for individuals who are aged 12 years or older who are immunocompromised and who have received a first booster dose of any approved or authorized COVID-19 vaccine.

Reference

Pfizer and BioNTech advance COVID-19 vaccine strategy with study start of next-generation vaccine candidate based on enhanced spike protein design. News release, Pfizer. July 27, 2022. Accessed July 28, 2022. https://www.pfizer.com/news/announcements/pfizer-and-biontech-advance-covid-19-vaccine-strategy-study-start-next