LONDON – Biontech SE announced positive preliminary data from the ongoing phase I/II trial of one of the four COVID-19 vaccines it is developing with Pfizer Inc., with participants in each of three dose groups mounting immune responses that were greater than seen in patients who recovered from COVID-19 infections.
The two companies said they are on track to begin a phase IIb/III study involving up to 30,000 healthy volunteers before the end of July, and if successful, expect to manufacture 100 million doses by the end of 2020 and potentially more than 1.2 billion doses by the end of 2021.
The four vaccine candidates being evaluated each have a different combination of messenger RNA format and target antigen, with the preliminary data released on July 1 relating to BNT-162b1, which encodes a SARS-CoV-2 receptor binding domain (RBD) antigen.
Taken overall, the results from the 45-subject U.S. arm of the trial demonstrate BNT-162b1 was well-tolerated and generated dose-dependent immunogenicity, as measured by both SARS-CoV-2 neutralizing antibodies and RBD immunoglobulin G (IgG) concentration.
The data are positive, but the study at the moment “has several limitations,” said Ugur Sahin, CEO and co-founder of Mainz, Germany-based Biontech.
A key unknown is the correlates of protection that will render a vaccinated person immune to SARS-CoV-2. “We have high neutralizing antibody titres, but we don’t know if there will be protection,” Sahin told attendees of a teleconference held to discuss the data.
Immunogenicity was assessed by referencing a panel of sera from 38 recovered COVID-19 patients. Sahin said that included patients with more and less severe infections, and compared to published studies seems to represent the spectrum of disease. “We believe the collection of sera is a good representation of the disease course of COVID-19 patients, including those that do not require hospitalization,” he said.
In addition, there is no information as yet on T-cell responses. Sahin said those are being assessed in the German arm of the trial and will be published within the next few weeks.
Shares of Biontech (NASDAQ:BNTX) were trading up 9% at midday.