French drugmaker Sanofi (NASDAQ: SNY) and partner British pharmaceutical giant GlaxoSmithKline (NYSE: GSK) announced last week the companies are seeking regulatory approval for their COVID-19 vaccine to be used as a booster, as well as a initial two-dose regimen, possibly adding a fourth effective vaccine option for Americans.
Shaking off several setbacks, the companies said they intend to submit data to regulators--including the U.S. Food and Drug Administration and European Medicines Agency--from their late-stage clinical trial of the vaccine and another for its use as a booster. Full results from both studies are expected to be published later this year.
"The evolving epidemiology of COVID-19 demonstrates the need for a variety of vaccines," said Roger Conner, president of GSK Vaccines, in a press statement. "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."
The vaccine candidate uses an adjuvanted protein-based technology, similar to common vaccines used to prevent the seasonal flu; Sanofi developed the vaccine, while GSK supplied the adjuvant technology to boost the effectiveness of the shot under the pair's partnership. This vaccine uses a more traditional approach compared to new mRNA technologies used in current vaccines developed by Pfizer (NYSE: PFE)-BioNTech (NASDAQ: BNTX) and Moderna (NASDAQ: MRNA).
The companies said final analysis of their booster trial, which included participates previously dosed with vaccines using mRNA or traditional adenovirus technology, showed the shot could increase neutralizing antibodies by 18- to 30-fold across vaccine platforms and age groups.
Moreover, early-stage data on its vaccines used as a two dose primary series in previously unvaccinated volunteers demonstrated 100% efficacy against severe COVID-19 disease and hospitalization, 75% efficacy against moderate or severe disease, and 57.9% efficacy against any symptomatic disease.
When the Sanofi-GSK vaccine was used as a two-dose primary series followed by a booster dose, neutralizing antibodies increased 84- to 153-fold compared to pre-booster levels.
"We also observed robust efficacy of the vaccine as a primary series in today's challenging epidemiological environment," said Thomas Triomphe, executive vice president at Sanofi Vaccines, in a press statement. "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 disappointed investors back in December by delaying data from the pair's booster trial to this year. Sanofi had previously dropped plans for its own mRNA vaccine due to its weak performance compared to vaccines developed by Pfizer-BioNTech and Moderna.