Pfizer and BioNTech have revealed additional data from a phase 1 study of two of its COVID-19 vaccine candidates, as well as their plans to potentially seek regulatory approval by October this year.
At the beginning of July, Pfizer/BioNTech revealed early positive data from their mRNA-based COVID-19 vaccine programme. Those results demonstrated that one of the candidates, BNT162b1, generated promising dose-dependent immunogenicity.
However, the companies somewhat surprised commentators when they announced that another candidate, BNT162b2, had been selected for a large-scale, phase 3 clinical trial.
In additional data shared today, Pfizer/BioNTech posted the results from all 332 participants tested with the two mRNA-based candidates, BNT162b1 or BNT162b2, to clarify their decision.
That data showed that systemic events following administration of BNT162b were milder compared to those experienced with BNT162b1. Following the second dose of BNT162b2, only 17% of participants in the 18-55 years age group reported fever, compared to 75% in the same age group in the BNT162b1 arm.
Researchers tested a range of doses of the vaccines, but ultimately have decided to progress with 30-microgram dose of BNT162b2 in late-stage trials.
Despite both candidates eliciting similar antibody levels against the SARS-CoV-2 virus, which causes COVID-19, the favourable safety profile of BNT162b2 warranted its selection as the lead vaccine going forward.
“It is important to us to continue sharing data and related information on our COVID-19 vaccine lead candidate,” said Ugur Sahin, chief executive officer and co-founder of BioNTech.
“The favourable safety profile of BNT162b2 and the breadth of T cell responses we previously announced have supported our decision to select this candidate for the pivotal phase 2/3 study. As of today (21 August), we have already dosed more than 11,000 participants with BNT162b2 in that study,” he added.
Pfizer/BioNTech plan to enrol 30,000 participants into the phase 2/3 efficacy and safety trial, which is now actively enrolling in the US, Argentina and Brazil, with further planned enrolment in Germany, Turkey and South Africa.
If all goes to plan in this study, the companies have said they are on track to file for regulatory review for BNT162b2 as early as October and plan to supply up to 100 million doses globally by the end of the year if approval is obtained.