Omicron renders most monoclonal antibody therapies ineffective: study

New York- According to an international study involving researchers from the United States, Japan and Switzerland, monoclonal antibody therapy, once considered 100% effective in stopping Covid-19 in its tracks, has been defeated by the new super mutant variant Omicron from the coronavirus.

Monoclonal antibodies are proteins designed to bind to a specific target, in this case the SARS-CoV-2 spike protein, which the virus uses to enter human cells. Several studies have shown that monoclonal antibody therapy can stop the progression of Covid infection to intensive care admissions and death.

Cocktail therapy rose to fame after it was used to treat then-US President Donald Trump last October. It was also approved by the United States Food and Drug Administration in November of last year, and even by the Central Drugs Standards Control Organization (CDSCO) for use in India in May 2021.

A team of researchers analyzed the effectiveness of monoclonal antibody treatments from large pharmaceutical companies.

The results, published on the biorxiv preprint server, and not yet peer reviewed, revealed that the therapy developed by pharmaceutical giants like Regeneron, Lilly and Celltrion “has completely lost its neutralizing activity” in the face of Omicron.

However, monoclonal antibody treatments by AstraZeneca and Vir Biotechnology were “minimally affected” or in other words, “retained partial activity”.

The recent emergence of the highly transmissible variant B.1.1.529 Omicron is of particular concern due to the number of mutations – over 30 in the spike protein.

“Our results suggest that many, but not all, of the antibody products used clinically will lose their efficacy against the B.1.1.529 Omicron variant and related strains,” wrote corresponding author Michael S. Diamond, of Washington University School of Medicine. , in the study.

“Our experiences show a marked loss in the inhibitory activity of many of the more neutralizing monoclonal antibodies that are in advanced clinical development or have emergency use approval,” he added.

The researchers evaluated antibodies that correspond to monotherapy or combination therapy that have shown success before and after exposure in clinical trials and in patients infected with historical isolates of SARS-CoV-2.

The study is in tandem with preliminary studies showing that several antibodies used clinically lose their neutralizing activity against recombinant lentiviral or vesicular stomatitis virus (VSV) pseudoviruses expressing Omicron spikes, the researchers said.

Additionally, they noted that although monoclonal antibody treatments with AstraZeneca and Vir Biotechnology “in clinical use may retain benefits, in vivo validation experiments are needed to support this conclusion and inform clinical decisions”.

The study also noted several limitations such as experiments focused on the impact of large sequence changes in the spike protein B.1.1.529 on the neutralization of monoclonal antibodies in cell culture. Despite the observation of differences in neutralizing activity with some monoclonal antibodies, it remains to be seen how this finding translates into effects on clinical protection against Omicron. (IANS)