Sanofi, Glaxo Covid Shot Works as Booster But Stalls Again
(Bloomberg) -- Sanofi and GlaxoSmithKline Plc, the pharma giants that stumbled in the race to develop a Covid-19 shot, said their experimental vaccine works as a booster but suffered yet another delay with the main clinical trial results.
The booster raised the antibody levels of people who’d already received other inoculations such as Pfizer Inc.’s and AstraZeneca Plc’s, the drugmakers said in a statement Wednesday. Crucial test results for the underlying vaccine, meanwhile, were pushed back to the first quarter. Neither study pitted the product against the new omicron variant.
The two partners took the unusual step of saying their shot works as a booster before they could show it’s effective as a first-line immunization. More participants need to get Covid to wrap up the clinical trial, a delay that prevents the companies from seeking regulatory approval for the booster.
Sanofi and Glaxo, two of the vaccine industry’s biggest players, must show they still have a role to play in the pandemic after a dosing error forced them to restart a clinical trial. The vaccine is nearing the end of clinical trials, and countries may be reluctant to order doses before they see data on how well the initial product wards off infection -- particularly from omicron.
The booster is based on the original coronavirus strain. Data from another one developed with the beta variant will yield results in the first half of 2022, the companies said. Tests against omicron are underway.
“Given the rapidly evolving Covid-19 landscape, including the recent emergence of a likely more transmissible omicron variant, it is challenging to interpret this delay,” Peter Welford, an analyst at Jefferies, wrote in a note. One point that could “restore some belief” in the project would be to show that the vaccine offers durable protection, Welford and colleagues said, since the immunity from messenger RNA shots appears to wane after a few months.
Sanofi shares dropped less than 1% in Paris trading, as did Glaxo in London.
With roughly 8.5 billion shots having been administered around the world, the partners are pivoting toward selling a universal booster -- a vaccine that can work to revive the effect of any vaccine. But once again they’re lagging behind, with Pfizer and its partner BioNTech SE, along with Moderna Inc. and to a lesser extent Astra and Johnson & Johnson having secured regulatory approval for their follow-up shots already.
With omicron, the Covid vaccine world is once again in flux as it seeks to answer questions about vaccine efficacy. The U.K. and others are storming ahead with booster campaigns and the Pfizer-BioNTech team as well as Moderna are saying they could start shipping an updated version of their shots as soon as March.
Even without the new mutations, it’s hard to measure which booster shots work best. Each aims to multiply antibodies, often far above levels that people developed after their initial rounds of shots. Sanofi and Glaxo’s vaccine noted a 9- to 43-fold increase in neutralizing antibodies after their booster, which was safe and well tolerated, they said.
That result “is impossible to assess as there’s no agreement on how these relate to vaccine efficacy for regulatory approval,” said Sam Fazeli, head of research at Bloomberg Intelligence.
The Sanofi-Glaxo product relies on technology the French drugmaker uses to make flu vaccines and an adjuvant from the U.K. company to enhance the immune response. It can be kept at fridge temperatures, making it easier to transport and store than existing mRNA shots.
Sanofi CEO Paul Hudson said recently that the company already has sales agreements for about 75 million doses with European countries for the booster, provided clinical data supports its use.
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