AstraZeneca says drug efficacy against Covid-19 exceeds 80%

The pharmaceutical company AstraZeneca announced, in an official statement on Thursday (18), that its monoclonal antibody AZD7442 was able to reduce the risk of symptomatic Covid-19 and also the risk of developing a severe condition and death.

Monoclonal antibodies are, in short, proteins designed to specifically attack a target.

The company presented data, not yet peer-reviewed, from two randomized, double-blind, control-group studies. In one of them, designed to observe the potential of exposure prophylaxis of the biological drug, more than 5,000 adults considered to be at increased risk of contracting Covid or at risk of inadequate responses to immunization, such as people with cancer undergoing chemotherapy, patients on dialysis and who takes immunosuppressive drugs.

According to AstraZeneca, more than 75% of participants in this study have comorbidities that put them at high risk for severe Covid if they become infected.

At a 300 mg intravenous dose of the combination (AZD7442) of its monoclonal antibodies tixagevimab and cilgavimab, the drugmaker says it has seen an 83% reduction in the risk of developing symptomatic Covid compared to the placebo group.

In the group that took the biological medicine, there were no records of deaths due to Covid or serious conditions, with an analysis period that extends for six months.

In the placebo arm of the study, five cases of severe Covid and only two deaths were recorded. The study took place with people from the USA and Europe.

In the other study, also released this Thursday (18) and still without peer review, the company analyzed the potential of using the combination of monoclonal antibodies in the treatment of adults with laboratory confirmation of mild to moderate Covid, without the need for hospitalization and symptoms for seven days or less.

In this case, the pharmaceutical researchers applied twice the dose of antibodies (600 mg) and observed an 88% reduction in the risk of developing severe Covid or death, compared to the placebo group. The people were followed for 29 days and the follow-up will continue for 15 months.

According to the company, in that second study, about 13% of participants were 65 years or older and 90% of them had comorbidities that increase their risk for serious Covid, such as cancer, diabetes, obesity and cardiovascular disease.

AstraZeneca states that, overall, AZD7442 was well tolerated.

The pharmacist also says that the data will be submitted for peer review and publication in scientific journals.

It is noteworthy that the drug does not replace the need for vaccination against the new coronavirus.

Previously, in preliminary analyses, AstraZeneca had already announced that the treatment was up to 77% effective against the risk of developing symptomatic Covid.

This is not the only monoclonal antibody that has tested positive against Covid.

One of them is Regen-Cov (combination of casirivimab and imdevimab), by the pharmaceutical company Regeneron, which is approved for emergency use in Brazil.

According to a study published in The New England Journal of Medicine, the biological medicine managed to reduce cases of Covid in residents of the same house where there were patients diagnosed with the disease. It was also able to prevent hospitalizations and deaths in people at risk for severe disease.

Already the monoclonal antibodies developed by pharmaceutical Eli Lilly managed to reduce by up to 70% the risk of hospitalizations and deaths due to Covid. The combination of eanlanivimab and etesevimab is also approved by Anvisa (National Health Surveillance Agency).

There is also regdanvimab, a monoclonal antibody from Celltrion Healthcares, and, finally, sotrovimab, a biological drug from GlaxonSmithKlein (GSK), both with authorization for emergency use by Anvisa. These have shown considerable reductions in the risk of disease progression in people aged 12 years and older and with a high chance of worsening Covid.