Sanofi and GSK’s vaccine is said to have induced superior immune responses and a favourable safety profile, both as a two-dose primary series, and a booster dose
Sanofi-GSK vaccine showed efficacy in Phase 3 trial. (Credit: pearson0612 from Pixabay)
French drugmaker Sanofi, together with its partner GSK, is seeking regulatory approval for their adjuvanted recombinant protein-based Covid-19 vaccine candidate.
The partners intend to submit the data from both their booster and Phase 3 efficacy trials to support regulatory applications for their vaccine.
In the trials, the Sanofi-GSK vaccine is said to have induced superior immune responses and a favourable safety profile in multiple settings, both as a two-dose primary series, and a booster dose.
A booster dose of the vaccine, administered after a primary series of an authorised mRNA or adenovirus vaccine, induced 18 to 30 times increased neutralising antibodies.
The Sanofi-GSK vaccine, when used as a two-dose primary series followed by a booster dose, induced 84 to 153 times more neutralising antibodies compared to pre-boost levels.
In addition, the vaccine is said to have delivered high levels of neutralising antibodies when used as a two-dose primary series, compared to a panel of sera from volunteers who received the primary series of mRNA vaccine.
The vaccine as primary series showed GMTs reaching 3711 units, compared to a GMT of 1653 units from volunteers who received mRNA vaccine.
Sanofi Vaccines executive vice president Thomas Triomphe said: “We’re very pleased with these data, which confirm our strong science and the benefits of our Covid-19 vaccine.
“The Sanofi-GSK vaccine demonstrates a universal ability to boost all platforms and across all ages. We also observed robust efficacy of the vaccine as a primary series in today’s challenging epidemiological environment.
“No other global Phase 3 efficacy study has been undertaken during this period with so many variants of concern, including Omicron, and these efficacy data are similar to the recent clinical data from authorized vaccines.”
Sanofi and GSK have initially collaborated in April 2020 to develop an adjuvanted vaccine for Covid-19 using advanced technology from both companies.
Under the collaboration, Sanofi provides its recombinant antigen and GSK provides its pandemic adjuvant, where both vaccine platforms have shown positive outcomes against influenza.
In the Phase 3 efficacy study (VAT08), two doses of the Sanofi-GSK vaccine demonstrated the efficacy of 57.9% against any symptomatic Covid-19 disease in the seronegative people.
The vaccine offered 100% protection against severe disease and hospitalisations and 75% efficacy against moderate-to-severe disease in seronegative populations.
Interim results from the Phase 2 trial showed that the vaccine induced 95% to 100% seroconversion after the second dose, and was well tolerated with no safety concerns.
Currently, Sanofi and GSK are in talks with regulatory authorities, including the US FDA and European Medicines Agency (EMA), to support the regulatory approval of the vaccine.
GSK Vaccines president Roger Connor said: “The evolving epidemiology of COVID-19 demonstrates the need for a variety of vaccines.
“Our adjuvanted protein-based vaccine candidate uses a well-established approach that has been applied widely to prevent infection with other viruses including pandemic flu.
“We are confident that this vaccine can play an important role as we continue to address this pandemic and prepare for the post-pandemic period.”