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Health Canada issues treatment failure warning for COVID therapy due to BA.2 subvariant

Toronto -

Health Canada is alerting health-care providers that a COVID-19 monoclonal antibody therapy treatment may no longer be effective against the new subvariant of Omicron.

The agency reported on Thursday that sotrovimab, manufactured by GlaxoSmithKline and Vir Biotechnology, "is unlikely to maintain efficacy against the Omicron BA.2 subvariant," and said that the treatment exhibited "a reduction in activity" against the new subvariant.

However, Health Canada says sotrovimab can still be administered to COVID-19 patients who test positive for the earlier subvariants of Omicron.

"Current data indicates that sotrovimab continues to be effective against the Omicron BA.1 and BA.1.1 subvariants," the agency said. "Local epidemiology and individual exposure to variants should be taken into consideration before use of sotrovimab."

Sotrovimab was authorized for emergency used in relation to the pandemic last July for treatment of mild to moderate cases of COVID-19 in adults and adolescents 12 years of age or older who are at a high risk of hospitalization or death.

The alert comes a week after the U.S. Food and Drug Administration pulled its authorization for the therapy due to rising cases of the BA.2 subvariant across the country.

Provincial health authorities have already been pulling or discouraging the treatment, instead recommending Paxlovid or Remdesivir.

The Ontario Science Table recommended against using Sotrovimab on April 1 and Alberta paused the use of the treatment on Wednesday. Saskatchewan also discontinued the use of sotrovimab on April 7 and B.C. only recommends the treatment "as a last-line agent."


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