A two-stage Phase III clinical trial by Sanofi and GSK, is studying a COVID-19 vaccine candidate targeting the original SARS-CoV-2 strain as well as the South African B.1.351 variant.
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A two-stage Phase III clinical trial recently launched by Sanofi and GlaxoSmithKline (GSK) is studying a COVID-19 vaccine candidate targeting the original SARS-CoV-2 strain as well as the South African B.1.351 variant.
The partnership between the two companies sees Sanofi providing its recombinant antigen and GSK contributing its pandemic adjuvant, both of which have shown successful efficacy against influenza strains.
Sanofi and GSK plan to enroll more than 35,000 volunteers from the U.S. and countries across Asia, Africa, and Latin America. Considering that the vaccine will be tested across multiple global sites, the investigators will also evaluate the efficacy of the vaccine candidate against several other circulating variants.
Previously announced interim results from a Phase II study showed the adjuvanted recombinant vaccine was associated with high neutralizing antibody response rates in all adult age groups. In addition, the vaccine was associated with 95% to 100% seroconversion rates. The investigators also observed the generation of high neutralizing antibody levels in participants who had evidence of previous SARS-CoV-2 infection, hinting at the possibility that the candidate could form the basis for a booster vaccine development.
In the new late-stage clinical trial, researchers will look to determine if the COVID-19 vaccine candidate can prevent symptomatic COVID-19 in adults who have had no prior infection with the novel coronavirus. Secondary endpoints of the trial include prevention of severe COVID-19 disease as well as asymptomatic infection.
Federal funds from the Biomedical Advanced Research and Development Authority (BARDA) are supporting the new research initiative. The Authority is part of the office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services. It is in collaboration with the U.S. Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological, and Nuclear Defense.
“We are encouraged to see first vaccinations starting to take place in such an important, pivotal Phase III study, as we believe that our unique technology platform will provide a clinically-relevant vaccine option,” according to a statement made by Thomas Triomphe, Sanofi Pasteur’s Executive Vice President and Global Head.
“Adjusting our technology and study designs reflects this need and will further build the potential of this adjuvanted protein-based vaccine,” added Roger Connor, President of GSK Vaccines.
If the findings from the Phase III study are positive, the vaccine from Sanofi and GSK could be authorized or approved by the fourth quarter of this year. The two companies said in a statement that manufacturing of the vaccine is set to start “in the coming weeks to enable rapid access to the vaccine should it be approved.”
Back in December, the two European drugmakers were forced to halt their trial due to lackluster results in a study of older adults. The findings showed that the COVID-19 vaccine produced insufficient immune responses in these older participants, demonstrating the unique challenges faced by Sanofi and GSK in the collaborative effort to develop an effective vaccine quickly during a rapidly evolving pandemic.
