Sanofi, Glaxo announces setback in coronavirus vaccine project

Sanofi and GlaxoSmithKline (GSK) on Friday announced a setback in their coronavirus vaccine project, saying they now expect their vaccine to be available next year.

The companies said in a joint statement that interim results from a phase 1/2 trial showed the vaccine produced a low immune response in older adults, which it said was likely due to an insufficient concentration of the antigen.

The vaccine did elicit an immune response in adults 18-49 years old that the companies said was comparable to that seen in recovered COVID-19 patients.

U.K.-based GSK and French company Sanofi said they will conduct a phase 2b study in February 2021. Phase 3 confirmatory trials, which were originally slated for this month, are now expected to begin by the second quarter of 2021.

The companies now think the vaccine will be available from mid-2021 to the fourth quarter of 2021. They were originally planning to begin the trial this month.

The phase 1/2 study tested the vaccine in 441 adults in the U.S. The participants received either one or two doses of the vaccine or a placebo, 21 days apart.

“The results of the study are not as we hoped,” Roger Connor, president of GSK Vaccines, said in a statement. “Our aim now is to work closely with our partner Sanofi to develop this vaccine, with an improved antigen formulation, for it to make a meaningful contribution to preventing COVID-19.”

Sanofi and GSK received a $2.1 billion contract from the U.S. government in July for development of their vaccines and to produce 100 million doses. 

The companies said they are updating governments and the European Commission where contractual commitments to purchase the vaccine have been made.

The setback for the companies comes just a day after a Food and Drug Administration (FDA) panel endorsed a coronavirus vaccine from Pfizer and BioNTech, and recommended that the FDA move forward with emergency authorization.