Sanofi, GSK push COVID-19 vaccine data into 2022. Will strong booster data hold their place in line?

Sanofi and GlaxoSmithKline are delaying full booster data for their combined COVID-19 vaccine into the first quarter of 2022, a readout that has been eagerly anticipated by investors and analysts.

The companies said most patients in the trial had been recruited amid a sharp rise in cases during the third quarter caused by the delta variant. They need more data on volunteers who have never tested positive for the disease to submit to regulators. Therefore, an independent data monitoring committee has recommended the trial continue into 2022 to record more symptomatic COVID-19 events.

News of the delay came as the companies said their shot provided protection when used as a booster after a primary course of one of the authorized vaccines. Those include the shots made by Pfizer and BioNTech, AstraZeneca, Johnson & Johnson and Moderna.

Sanofi and GSK missed the boat on getting a shot ready for authorization early in the pandemic, leaving them in catch-up mode to hit the booster market. Their candidate has been moving through development slowly with several delays along the way.

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Enrollment for the phase 3 VAT0008 study ended at 10,000 participants back in the third quarter. Sanofi and GSK had initially been targeting 16,000, but the wave of infections caused by the delta variant made recruitment more difficult, the companies said in a Wednesday statement.

Analysts from Jefferies noted the rapidly changing nature of the pandemic. While the delay is caused by the delta variant, another potentially more transmissible variant called omicron is already spreading around the world.

“It is challenging to interpret this delay, in our view,” Jefferies said.

But Jefferies was impressed by the booster data, although missing from the study was any information on omicron. A different test is underway to see how the Sanofi-GSK shot fares against that variant. Jefferies also noted that the durability of the mRNA shots still has not been established, so Sanofi and GSK may be able to make their mark as a long-lasting option.

RELATED: GlaxoSmithKline, Medicago hit 75% efficacy against delta COVID strain, but omicron muddies waters

Should Sanofi and GSK manage to get their vaccine through a rolling submission, Jefferies sees only upside for sales. The U.K. has already signed a commitment for 75 million doses, while the U.S. has locked in 100 million. 

GSK is not putting all its eggs in one basket, either. The company recently reported efficacy of 75% for a candidate under development with Medicago that was based on the delta strain. 

Meanwhile, Sanofi continues to manufacture a half billion doses of the vaccines made by Pfizer-BioNTech, Johnson & Johnson and Moderna at its facilities.