Mayo study finds new monoclonal antibody is effective against omicron variants
Bebtelovimab is designed as a treatment option for those newly diagnosed with COVID-19 who cannot take Paxlovid and are deemed at high risk of severe outcomes. It replaces a series of monoclonal
ROCHESTER, Minn. — Researchers at the Mayo Clinic have announced positive results from the largest clinical trial of bebtelovimab, an FDA-approved monoclonal antibody for the treatment of COVID-19 among high risk patients.
The findings were published on Monday, Aug. 15, in the Journal of Infectious Diseases. The clinical trial reported the results of 2,833 patients given bebtelovimab and 774 patients prescribed Paxlovid within five days of symptoms. The study learned that only 1.4% of those given bebtelovimab progressed to serious disease within 30 days, which is comparable to the protection provided by early use of Paxlovid.
While just 0.2% of those given Paxlovid were admitted to the ICU, 0.4% of those who received bebtolovimab required intensive care for COVID-19, the study reported.
Monoclonal antibodies are lab-designed proteins created to mimic the body's immune system responders charged with facing invading pathogens. Because they are tailored specific to individual viruses, which mutate, they become ineffective as the virus goes through even small changes.
The Mayo finding builds on prior lab research suggesting the effectiveness of bebtelovimab against omicron subvariants. It is the only monoclonal antibody that remains effective for COVID-19 following a series of mutations which have led to BA.2 as the current dominant omicron variant.
The new infusion provides an alternative for those who cannot take oral Paxlovid due to drug interactions. Because it requires just one 1-minute infusion, it is also considered preferable to remdesivir, a drug given in three infusions over as many days.
Paxolovid, remdesivir and bebtelovimab are offered to those who are in the first days after testing positive for COVID-19 and are deemed high risk of serious outcomes. That group includes all persons age 65 and older, as well as those with diabetes, hypertension, or chronic heart, kidney or lung disease, among other illnesses.
The drug is supplied to participating infusion centers by the federal government, which purchased 600,000 doses from drugmaker Eli Lilly in February. Lilly acquired bebtelovimab after it was developed by research from the National Institute of Allergy and Infectious Disease in concert with the Canadian biotech firm AbCellera.
"In a population that is considered high risk and not able to take Paxlovid, the use of bebtelovimab is as good as Paxlovid," summarized Dr. Raymund Razonable, Mayo Clinic infectious disease specialist and lead author of the study. "The outcomes remain very good with low rate of hospitalization and death, similar to what we have observed for the other monoclonal antibodies that were effective before the omicron surge."
"It was authorized by the FDA in February of this year, however that authorization was based on experimental data in the lab with not really a lot of clinical research to support its use ... So [now] we believe this remains effective and should be available to patients who qualify and who don't have any other choice of treatment."