Sanofi, Glaxo Covid Vaccine Works Well in Second-Chance Test


Sanofi and GlaxoSmithKline Plc reported positive results from a redo of a mid-stage study for their Covid-19 vaccine, putting the delayed shot on track for possible clearance by the end of the year.

Volunteers showed a similar immune response to people who have recovered from the coronavirus, Sanofi said Monday. Those who’d already been infected had a higher response after just one injection, prompting the companies to decide to test a second formulation to bring to market as a booster.

The results come as a relief for the partners, two of the biggest and most experienced companies in the vaccine field whose effort stumbled late last year when a dosing error delayed the initial study. Glaxo’s stock rose in London trading, as did Sanofi’s in Paris.

The improved shot, which relies on technology used to make flu vaccines, could win regulatory approval in the fourth quarter, roughly a year after the one developed by Pfizer Inc. and BioNTech SE. Since then, a handful of other injections have received clearance. But as the world faces a growing number of variants and many countries struggle to get enough doses to immunize their population, the product could still play an important role -- especially since it can be stored in a fridge.

“There have been so many unexpected twists and turns to this story,” said Thomas Triomphe, head of Sanofi’s vaccines unit. “We know the world today needs more than one platform to address the global need.”

Next Steps

The new test enlisted 722 adults, from teens to 95-year-olds, in the U.S. and Honduras. Three different vaccine doses were injected three weeks apart and evaluated. Adults under 60 fared better overall, and there were no safety concerns, the companies said. They only released partial data from a part of the study results that tested the shot against the original virus strain, but said more details and data against variants would be published soon.

Now Sanofi and Glaxo plan to move on to a final-stage trial involving about 37,000 participants from a range of countries. The study will begin in the coming weeks using the middle of the three dosage strengths and test the injection against a placebo rather than a rival shot to answer regulators’ requirements.

The test will assess the shot against a number of variants, including the ones first discovered in India and South Africa. The vaccine formulation itself includes the South African strain in addition to the original one, according to Triomphe.

Sanofi and Glaxo said they plan to conduct a separate series of studies to seek clearance for a universal booster -- meaning a shot that can work to revive the effect of any vaccine. The goal is to also gain approval for that product in the fourth quarter.

Sanofi supplies the same recombinant approach it uses against seasonal flu while Glaxo manufactures the adjuvant that enhance the body’s immune response.

After the unexpected clinical trial delay last year, the companies opted to help other drugmakers manufacture their own immunizations. Glaxo has agreed to produce as many as 100 million doses of CureVac NV’s messenger RNA shot, while Sanofi is supporting the production for Moderna Inc., Pfizer Inc. and Johnson & Johnson. Sanofi is also working on a second shot using mRNA, with early trial results expected in the third quarter.

©2021 Bloomberg L.P.

BQ Install

Bloomberg Quint

Add BloombergQuint App to Home screen.