"Preliminary tests indicate the Covid-19 antibody drug cocktail from Regeneron Pharmaceuticals Inc. loses effectiveness against Omicron, the company said Tuesday, a sign that some products in an important class of therapies might need modifying if the new strain becomes widespread.
Separate testing of another authorized Covid-19 antibody drug cocktail, from Eli Lilly & Co., indicates it also isn't as effective against Omicron, outside scientists said. Lilly said it is testing the new variant against its antibody treatment and wouldn't speculate on what the results will be.
The findings are the early results of researchers' race to assess the impact of the new Omicron variant on Covid-19 treatments that patients, doctors and hospitals have been relying on, as well as pills in development that have promised to keep people out of the hospital.
Researchers say some antibody therapies are likely to be especially vulnerable to Omicron because it contains mutations to the spike protein that the Regeneron and Lilly drugs target, while other drugs should hold up well because they attack elements of the virus unchanged in the variant.
Monoclonal antibodies are lab-made molecules derived from survivors of Covid-19 or mice engineered to have human immune systems. When given soon after infection, the drugs attach to the surface of the coronavirus and prevent it from replicating itself in new cells.
They are the only drugs authorized to treat patients, before they require hospitalization, who are at high risk of developing severe cases.
The drugs differ from vaccines, which train the immune system how to defend against the virus, including with the production of antibodies. Last year, former President Donald Trump credited Regeneron's drug with his speedy recovery from Covid-19.
Regeneron said it would be able to quantify the impact of the variant in coming weeks, after further testing is done.
If final testing shows that its antibody drugs are less effective against Omicron, Regeneron has developed alternative antibodies that it can push into clinical testing and that it thinks will retain effectiveness against the variant, said George Yancopoulos, the company's president and chief scientific officer.
One of Regeneron's alternative antibodies is already in clinical testing, which the company began in anticipation of new variants emerging over time.
The Omicron variant was identified last week by scientists in South Africa, prompting drug researchers to scramble to see if the relatively small medicine chest of Covid-19 treatments would still work against the new strain.
"What we have to admit is, in the course of the past six days, our urgency has increased," Dr. Yancopoulos said. "What started out as a backup plan has now been made a lot more urgent."
Scientists at the Fred Hutchinson Cancer Research Center in Seattle found that individual mutations from Omicron reduced or eliminated the ability of Regeneron's and Lilly's drugs to attach to the virus, said Allie Greaney, a Ph.D. candidate at the center and the University of Washington in Seattle.
More comprehensive tests of the drugs against the entire variant are needed to fully understand the impact, she said.
Lilly is in the process of testing the new variant against its drug, a combination of two antibodies called bamlanivimab and etesevimab, said Nicole Kallewaard, a Lilly virologist and research adviser. She declined to comment on the results showing reduced effectiveness against individual Omicron mutations, because the results may differ when all of the mutations are combined.
A rise in the prevalence of Omicron could present an opportunity for competitors who say their drugs don't appear in preliminary testing to be affected by the variant, including Vir Biotechnology Inc. and GlaxoSmithKline PLC, whose drug sotrovimab was authorized for emergency use earlier this year.
Fred Hutchinson researchers also said their initial testing indicated the Vir-GSK antibody drug retained its effectiveness. Adagio Therapeutics Inc., a biotech with a Covid-19 antibody drug in clinical trials, said its antibody also appears to be unaffected by the new variant. Vir, Glaxo and Adagio said they are conducting further tests.” [1]
1. U.S. News: Drug Cocktails Said to Lose Effectiveness Against Strain
Walker, Joseph. Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 01 Dec 2021: A.7.
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