The companies’ late-stage stumble could allow Moderna to widen its lead, with its mRNA-based combination vaccine eliciting superior immune responses against COVID-19 and three influenza strains.
Pfizer and BioNTech on Friday announced that their investigative mRNA combination vaccine for influenza and COVID-19 met only one of its two primary immunogenicity endpoints, forcing the partners to consider “adjustments” to the candidate.
The companies did not provide specific data in their announcement but revealed that compared with a commercially licensed flu shot, the mRNA vaccine elicited lower seroconversion against the influenza B strain. At the same time, Pfizer and BioNTech’s investigational shot was able to produce “robust influenza A responses” and a “continued higher trend” of immunogenicity against this strain versus a licensed vaccine.
The combination vaccine candidate also met its second primary immunogenicity endpoint, triggering a non-inferior response against the SARS-CoV-2 virus compared to the companies’ COVID-19 vaccine Comirnaty.
Despite missing one primary endpoint, Pfizer’s head of vaccine R&D Annaliesa Anderson struck an optimistic note in a statement, saying that the companies are “encouraged” by the immunogenicity seen against influenza A. According to Anderson, this response “was similar to what we had seen for our initial quadrivalent influenza vaccine.”
Still, with the underwhelming influenza B response, the partners are now “evaluating the next steps” for the combo vaccine candidate, including potential “adjustments” to its formulation to potentially improve the immune response against this specific strain. Pfizer and BioNTech will also work with regulatory authorities to identify the way forward for the candidate.
The late-stage stumble could cause added problems for BioNTech, which in its most recent Q2 business report announced a more than fourfold spike in losses—on top of several consecutive quarters of declining revenues. While the German biotech is mostly banking on its cancer pipeline to turn its fortunes around, the combination shot could also potentially help the company improve its balance sheet.
In its Q2 investor call, co-founder and CEO Uğur Şahin said that BioNTech was targeting approval for the combo vaccine in time for the 2025/2026 season.
Meanwhile, Pfizer and BioNTech’s mixed Phase III data could be a boon for Moderna, which is also working on a COVID-19-flu combo vaccine. In June 2024, Moderna announced that compared with commercially licensed vaccines, mRNA-1083 induced significantly stronger immune responses against SARS-CoV-2 and three flu virus strains—H1N1, H3N2 and B/Victoria. Moderna’s shot was also non-inferior to the comparator vaccine for the B/Yamagata flu strain.
Pfizer on Friday also revealed Phase II data for its second-generation trivalent influenza mRNA vaccine candidate, which triggered “robust” immune responses against the influenza A and B strains. The pharma will continue to advance this program in coordination with regulatory authorities.
