Lab test: Eli Lilly and Regeneron’s therapies lose their effectiveness with omicron

German researchers have observed that the COVID-19 therapies developed by Eli Lilly and Regeneron lose most of their effectiveness when exposed in laboratory tests to the omicron variant of the coronavirus.

The Cologne and Berlin-based group of scientists found that the protection of GlaxoSmithKline and Vir’s Xevudy antibody cocktail was maintained when exposed to omicron in a laboratory experiment, but that this was not the case with Lilly’s bamlanivimab and etesevimab. and Regeneron’s drug Ronapreve.

“The neutralizing activity of several monoclonal antibodies is strongly affected against the omicron variant and will limit treatment options for omicron-induced COVID-19,” the study authors note in the paper, which was published online Tuesday.

The results have not yet been reviewed for publication in a medical journal.

When asked about the results, Ely Lilly said she expected the effectiveness of her antibody combination to be lower.

“Due to the substitutions contained in the omicron variant spike protein, it appears that bamlanivimab with etesevimab will likely experience reduced neutralizing activity,” said a spokesperson.

The company is conducting its own tests of omicron, also including its experimental antibody bebtelovimab, and would report initial results as soon as possible.

Regeneron had no immediate comment.

Monoclonal antibodies

Last week, in a similar laboratory trial, a group of German-based researchers, including virologist Sandra Ciesek of the Frankfurt University Hospital, came to a similar conclusion about Regeneron’s drug, saying that omicron he was resistant to this therapy.

Regeneron herself said on November 30 that laboratory tests and computer modeling suggested that her COVID-19 antibody drug would have reduced efficacy against the omicron variant.

GSK and Vir have stated that laboratory tests performed on viruses carrying all omicron mutations indicate that their antibody drug would still be effective against the new variant.

The COVID-19 class of drugs known as monoclonal antibodies – bioengineered versions of natural proteins that fight the virus – are designed to adhere to the spike protein on the surface of the coronavirus, but omicron has been found to have an unusually high number of mutations in the spicule.

A similar product, AstraZeneca’s Evusheld, was granted emergency use authorization in the United States last week to prevent COVID-19 before any exposure to the virus, targeting those who respond poorly to vaccines due to a weakened immune system. .