Pfizer, along with BioNTech, has commenced the phase 2/3 safety and efficacy clinical study to assess a single nucleoside-modified messenger RNA (modRNA) candidate from their BNT162 mRNA-based vaccine programme against SARS-CoV-2.
Both companies have decided to advance their BNT162b2 vaccine candidate into the phase 2/3 study at a 30µg dose level in a two-dose regimen after an extensive assessment of preclinical and clinical data from phase 1/2 clinical studies and in consultation with the US Food and Drug Administration’s Center for Biologics Evaluation and Research (CBER) and other global regulators.
Recently, the BNT162b2 vaccine candidate secured fast track designation from the US Food and Drug Administration (FDA). It is said to encode an optimised SARS-CoV-2 full-length spike glycoprotein (S), which is the target of virus neutralising antibodies.
Pfizer vaccine research and development head and senior vice president Dr Kathrin Jansen said: “Our selection of the BNT162b2 vaccine candidate and its advancement into a Phase 2/3 study is the culmination of an extensive, collaborative and unprecedented R&D program involving Pfizer, BioNTech, clinical investigators, and study participants with a singular focus of developing a safe and effective Covid-19 RNA vaccine.”
The companies have selected BNT162b2 as the candidate to advance to a phase2/3 study based on the totality of available data from preclinical and clinical studies, including select immune response and tolerability parameters.
Preliminary clinical phase 1/2 data from nearly 120 patients showed a favourable overall tolerability profile for BNT162b2, as compared to BNT162b1, with generally mild to moderate and transient (1-2 days) systemic events such as fever, fatigue and chills and no serious adverse events.
The phase 2/3 trial is said to be designed as a 1:1 vaccine candidate to placebo, randomised, observer-blinded study to obtain safety, immune response, and efficacy data required for regulatory assessment.
According to the company, the study’s primary endpoints will be the prevention of Covid-19 in those who have not been infected by SARS-CoV-2 before immunisation, and prevention of Covid-19 regardless of whether participants have earlier been infected by SARS-CoV-2.
Secondary endpoints comprise of prevention of severe Covid-19 in those groups. The study will also examine the prevention of infection by SARS-CoV-2.
The phase 2/3 study is expected to be active at around 120 clinical investigational sites across the world by the end of the study. It will include 39 states across the US and countries including Argentina, Brazil, and Germany.
Also, the BNT162b2 is under clinical evaluation and is not presently approved for distribution across the world.
BioNTech CEO and co-founder Dr Ugur Sahin said: “Today, we are starting our late-stage global study, which will include up to 30,000 participants. We selected BNT162b2 as our lead candidate for this Phase 2/3 trial upon diligent evaluation of the totality of the data generated so far.”
In July, the US government placed an order worth $1.95bn to Pfizer and BioNTech to procure 100 million doses of their BNT162 vaccine candidate for Covid-19.