The US Food and Drug Administration (FDA) has awarded fast-track designations to two of Pfizer and BioNTech’s investigational COVID-19 vaccine candidates.
The two candidates, BNT162b1 and BNT162b2, are the most advanced investigational vaccines in Pfizer/BioNTech’s BNT162 mRNA-based vaccine programme, and are currently being evaluated in ongoing phase 1/2 clinical studies.
The FDA fast-track status was granted based on preliminary data from phase 1/2 studies that are currently ongoing in the US and Germany, as well as findings from animal immunogenicity studies. Initial clinical data for BNT162b1 demonstrated that the experimental vaccine was both well tolerated and generated dose-dependant immunogenicity.
The preliminary clinical data evaluated 24 subjects who received two injections of 10 µg and 30 µg, and nine subjects who received two doses of placebo control, 21 days apart. In addition to the participants who received two doses, another group received a single dose of 100 µg.
The BNT162 programme is evaluating at least four experimental vaccines, each of which represents a unique combination of messenger RNA (mRNA) format and target antigen. Both BNT162b1 and BNT162b2 are nucleoside modified RNAs, formulated in lipid nanoparticles. BNT162b1 encodes an optimised SARS-CoV-2 receptor-binding domain (RBD) antigen, while BNT162b2 encodes an optimised SARS-CoV-2 full-length spike protein antigen.
“The FDA’s decision to grant fast-track designation to these two COVID-19 vaccine candidates signifies an important milestone in the efforts to develop a safe and effective vaccine against SARS-CoV-2,” said Peter Honig, senior vice president, global regulatory affairs, Pfizer.
“We look forward to continuing to work closely with the FDA throughout the clinical development of this programme to evaluate the safety and efficacy of these vaccine candidates,” he added.
An FDA fast-track designation expedites the review of new drugs and vaccines that are intended to treat or prevent serious conditions and have the potential to address an unmet medical need. According to Pfizer, it expects to start a phase 2b/3 trial as soon as later this month, and are anticipating enrolling up to 30,000 subjects in the large-scale study.
Subject to efficacy and regulatory approval, Pfizer and BioNTech expect to manufacture up to 100 million doses of the successful vaccine candidate by the end of 2020 and potentially more than 1.2 billion doses by the end of 2021.
Pfizer and BioNTech were selected to join the US Department of Health & Human Services’ Operation Warp Speed (OWS) in June. The initiative aims to deliver 300 million doses of a safe and effective COVID-19 vaccine by January 2021, as part of a broader strategy to accelerate the development, manufacturing and distribution of COVID-19 vaccines, therapeutics and diagnostics.
Alongside Pfizer/BioNTech, AstraZeneca, Johnson & Johnson, Merck and Moderna were also selected to receive funding from OWS, with each company at different stages of clinical development.