Pharmaceutical Technology

Pfizer and BioNTech’s Covid-19/flu combination vaccine falters in Phase III readout

While the vaccine demonstrated high responses for neutralizing influenza A titers, it failed to show sufficient efficacy against influenza B.

Pfizer and BioNTech have announced that a Phase III trial studying their investigational combination mRNA vaccine for the treatment of influenza and Covid-19 has failed to meet one of its two primary endpoints.

While the vaccine demonstrated a trend of higher responses in neutralising the influenza A strain compared to a licensed influenza vaccine, it failed to demonstrate non-inferiority against the influenza B strain in geometric mean titers (GMT) and seroconversion, as per a 16 August press release. Additionally, data indicated that the combination vaccine showed “comparable” responses for SARS-CoV-2 when compared to Pfizer’s licensed approved Covid-19 vaccine, Comirnaty (tozinameran).

The randomised, parallel assignment Phase III study (NCT06178991) enrolled over 8,000 adults aged 18 to 64 years old to evaluate the safety, tolerability, and immunogenicity of a single dose of the combined vaccine for protection against influenza and Covid-19. No new safety signals were found in the Phase III study.

“Today’s results provide insight and direction towards achieving this goal, and we remain optimistic about our combination Covid-19 and influenza program, for which we are evaluating the next steps,” said Annaliesa Anderson, PhD, Senior Vice President and Head, Vaccine Research and Development at Pfizer.

Comirnaty, which gained full approval from the US Food and Drug Administration (FDA) in August 2021, is indicated for use in individuals aged 12 years and older for protection against Covid-19. The vaccine achieved peak sales of $42.4bn in 2022. However, there has been a decline in Covid-19 revenues in recent times, with pharma scrambling to make up the deficits.

In May, Pfizer announced a cost reduction programme to combat declining Covid-19 revenues, which was expected to save the company approximately $1.5bn by 2027. This measure came after the company announced in October 2023 that it would implement a $3.5bn cost-saving programme to combat a $5.5bn non-cash charge after the US government returned nearly eight million courses of the company’s Covid-19 antiviral pill Paxlovid (nirmatrelvir/ritonavir).

However, mRNA Covid-19 vaccines could continue to be in the news as the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) unanimously voted to update the existing Covid-19 vaccines, including Comirnaty, to target the JN.1 variant. Aside from Pfizer’s Comirnaty, the FDA has granted traditional approval to Moderna’s SpikeVax (elasomeran).