Regeneron’s mixture of two monoclonal antibodies lowered the danger of COVID-19–related hospitalization and dying from any trigger by 71% and resolved signs and diminished SARS-CoV-2 viral load quicker than a placebo, a section 3 scientific trial finds.
Within the research, revealed yesterday within the New England Journal of Drugs, a group led by Regeneron researchers randomly assigned 2,696 grownup COVID-19 outpatients at excessive threat for extreme sickness to obtain both intravenous REGEN-COV or a placebo from Sep 24, 2020, to Jan 17, 2021.
REGEN-COV is a 1:1 mixture of the monoclonal antibodies casirivimab and imdevimab.
Efficient no matter baseline antibody standing
Of 1,355 sufferers given 2,400 milligrams (mg) of REGEN-COV, 18 (1.3%) have been hospitalized or died from any trigger inside 28 days, in contrast with 62 of 1,341 sufferers (4.6%) given placebo (relative threat discount [RRR], 71.3%).
Seven of 736 sufferers (1.0%) who obtained 1,200 mg of REGEN-COV have been hospitalized or died, versus 24 of 748 (3.2%) of the placebo group (RRR, 70.4%). The REGEN-COV group was additionally much less more likely to require intensive care unit admission.
The researchers famous that earlier analysis has proven that REGEN-COV is efficient in vitro in opposition to variants of concern, together with Delta (B1617.2).
Sufferers given placebo who had SARS-CoV-2 antibodies at first of the trial had a comparable incidence of hospitalization and dying as those that had no antibodies, suggesting that some sufferers with antibodies mounted an ineffective immune response.
“Furthermore, this trial confirmed that REGEN-COV is related to scientific profit, no matter baseline serum antibody standing, in order that serologic testing on the time of the COVID-19 prognosis is much less crucial for making scientific remedy selections,” the research authors wrote.
Quicker symptom decision, decrease viral load
Signs within the REGEN-COV group resolved a median of 4 days quicker than within the placebo group, no matter dose (10 vs 14 days). Each doses of REGEN-COV additionally lowered viral load quicker than placebo.
The placebo group skilled extra severe opposed occasions (4.0%) than the 1,200-mg REGEN-COV group (1.1%) and the two,400-mg group (1.3%). Lower than 0.3% of sufferers in all teams had a reasonable or extreme infusion-related opposed response.
Median affected person age was 50 years, 14% have been 65 and older, 49% have been males, 35% have been Hispanic, and most had skilled signs for 3 days earlier than research enrollment. The most typical threat elements included weight problems (58%), age 50 and older (52%), and heart problems (36%), and three% have been immunocompromised. Most (69%) had no SARS-CoV-2 antibodies at baseline, and the median viral load was excessive, suggesting the early section of an infection.
The section 1/2 trial confirmed that the drug diminished each SARS-CoV-2 viral load and the variety of medical visits and that 2,400-milligram (mg) and eight,000-mg doses had comparable antiviral and scientific efficacy.
In November 2020 the US Meals and Drug Administration granted emergency use authorization to REGEN-COV for treating high-risk sufferers 12 and older who’ve reasonable to extreme COVID-19. The authorization was expanded for post-exposure prophylaxis in July 2021. The drug is free for eligible sufferers.