US drugmaker, Regeneron, in a partnership with Oxford University, has found that its new drug is capable of reducing COVID deaths by 20% when compared to standard treatments.
The drug, known as REGEN-COV, is a combination of two monoclonal antibodies known as casirivimab and imdevimab. Both antibodies bind to different sites on the coronavirus’s spike protein and prevent it from infecting healthy cells. Using both antibodies together reduces the chance of the virus becoming resistant to the treatment.
For the study, the researchers included 9,785 patients who were hospitalized with the SARS-CoV-2 virus. While half of the patients received REGEN-COV, the other half received standard treatment- either a steroid called dexamethasone or, for those with the most severe cases, an anti-inflammatory known as tocilizumab.
Roughly two-thirds of the patients were seropositive (meaning they had already developed COVID-19 antibodies before treatment) while the remaining third were seronegative.
In the end, the researchers found that seronegative patients who received REGEN-COV had hospital stays that were an average of four days shorter than those who received standard treatment. These patients were also less likely to need a ventilator. For patients who had developed antibodies, however, REGEN-COV had no effect.
The researchers say that upon admission to hospital, patients should now be tested for antibodies to help doctors decide which treatment is best for them. Testing for antibodies, says trial investigator Martin Landray, should be just as typical a procedure as testing for blood sugar, blood pressure and oxygen levels.
"These results are very exciting. The hope was that by giving a combination of antibodies targeting the SARS-CoV-2 virus we would be able to reduce the worst manifestations of COVID-19," said Sir Peter Horby, Joint Chief Investigator for the trial.
"There was, however, great uncertainty about the value of antiviral therapies in late-stage COVID-19 disease. It is wonderful to learn that even in advanced COVID-19 disease, targeting the virus can reduce mortality in patients who have failed to mount an antibody response of their own."
Sources: Regeneron, Fierce Pharma, The Economist
