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HomeHealth & FitnessMonoclonal antibodies may no longer be suitable for emerging COVID strains

Monoclonal antibodies may no longer be suitable for emerging COVID strains

Tixagevimab/cilgavimab (Evusheld) and bebtelovimab may not be effective against ~60% of currently circulating Omicron variants, creating a large gap in protection, especially in immunocompromised individuals, from Harvard Medicine A consortium of researchers led by the Academy said at a briefing on Thursday. tixagevimab-cilgavimab has emerged as an extremely important tool in the prevention of severe COVID and death in immunocompromised patients.

Tixagevimab-cilgavimab – Received Emergency Use Authorization in December 2021 as pre-exposure prophylaxis against COVID-19 in immunocompromised individuals and individuals with a history of severe vaccine reactions (PrEP) – Lost effectiveness for BQ.1 and BQ.1.1 and BA.4.6, BF.7, BA.5.2.6 and BA.2.75.2. As of November 12, these variants accounted for approximately 60% of the currently circulating Omicron variants. Mild to moderate COVID-19 at risk of developing severe disease – has lost potency against the subvariants BQ.1 and BQ.1.1 currently circulating in the US because they contain the spike K444T and R346T replacements.

“These are our last functional monoclonal antibodies,” Lemieux noted. “So I think it’s fair to say that the virus has outpaced the current generation of monoclonal antibodies. The race is likely to continue — and hopefully there will be some new products in the pipeline.”

Consortium co-leader Jeremy Luban, MD, of the University of Massachusetts Chan School of Medicine in Worcester, noted that cancer patients receiving aggressive treatment, transplant recipients, and patients receiving immunosuppressive therapy will experience a loss of these potent drugs.

“If you know someone who has cancer or is otherwise immunocompromised, it’s scary not having that,” he said. “This is a big problem.”

NIH COVID-19 Treatment Guidelines Panel Recommendations Recently Updated to Reflect Lack of Alternatives to PrEP and Bebtelovimab in the Face of These Emerging Strains.

“The panel continues to recommend tixagevimab plus cilgavimab as PrEP for eligible individuals,” the panel members wrote. However, the decision to use a drug should be based on “the regional prevalence of drug-resistant subvariants, individual patient risk, available resources, and logistics.”

In addition, those receiving treatment “should take precautions to avoid exposure to SARS-CoV-2,” they added. “

However, one of the challenges is knowing how to treat patients when you don’t know what variant they have, said Kathryn Stephenson, MD, MPH, co-leader of the alliance. Beth Israel Deaconess Medical Center, Boston. “Over a period of time, almost one variant supersedes the previous one, so you almost always know [what variant someone has]. Now, in the sense that the diversity of viral transmission or variants is more interesting, it becomes very important. ”

“It would be interesting to see if we could do faster sequencing diagnostics—if it was possible to know in real time “what does my patient have,” she added. things to do in clinical practice. “

Vaccination remains the most effective tool available today, Stephenson said. “Now that most people in the United States have received the primary series of vaccines, their risk of developing severe disease has decreased. “

The bigger problem is with immunocompromised people, she points out. “We’re going to have to do other things because monoclonal antibodies don’t work for us right now. “

Ritonavir-nirmatrelvir (Paxlovid ) and remdesivir (Veklury) remain the treatment of choice for patients infected with COVID-19 who are at risk of severe illness, as recommended by the NIH panel (press in order of priority).

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    Ingrid Hein is a staff writer for MedPage Today covering infectious disease. She has been a medical reporter for over a decade. Follow



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