Pfizer and BioNTech have reported positive early safety and immunogenicity data from the Phase I clinical trial of their second Covid-19 vaccine candidate, BNT162b2, in the US.
The companies previously announced promising results of the BNT162b1.
Latest data showed that 30μg of BNT162b2, seven days after the second dose, induced SARS-CoV-2-neutralising geometric mean titers (GMTs) in adults aged between 18 and 55 years.
The measure was 3.8 times the GMT of a panel of 38 sera of convalescent patients.
In older adults aged 65-85 years, the vaccine candidate triggered a neutralising GMT 1.6 times the GMT of the same panel, recording strong immunogenicity in the evaluated patient populations.
Also, the vaccine candidate was well tolerated across all populations, with mild to moderate fever in less than 20% of the subjects.
Based on these data, the companies decided to advance a two-dose regimen of 30µg BNT162b2 into a Phase II/III trial, which is currently enrolling participants in the US, Argentina and Brazil.
The vaccine candidate encodes an optimised SARS-CoV-2 full-length spike glycoprotein (S).
Pfizer senior vice president and vaccine research and development head Kathrin Jansen said: “The totality of the clinical and preclinical data-informed Pfizer and BioNTech’s decision to select BNT162b2 as the lead candidate to advance into pivotal trials. We are proud to share our findings with the scientific community as we continue our work to deliver a safe and effective vaccine to combat this devastating virus.
“We are especially pleased to offer these early data showing our vaccine candidate’s promising safety and immunogenicity profile from the US trial and we look forward to sharing T cell immune response data from the German trial in the near future.”
Pfizer and BioNTech are reviewing results from the Phase I trials of the Covid-19 vaccine candidates in the US and Germany.
Also, the additional data from the ongoing US Phase I study was used to assess the safety and immunogenicity of 10μg, 20μg or 30μg dose levels of BNT162b1 and BNT162b2 in 195 participants.
In younger and older adults, the vaccine candidates were observed to elicit similar dose-dependent SARS-CoV-2–neutralising antibody GMTs, which were elevated following the second dose, indicating the benefits of a two-dose regimen.