A synthetic antibody treatment developed by Regeneron reduced the risk of developing symptomatic Covid-19 by more than 80 per cent up to eight months after receiving the treatment, the US biotech firm said on Monday.
The results are “particularly important to those who do not respond to Covid-19 vaccines, including people who are immunocompromised”, said Myron Cohen, a University of North Carolina at Chapel Hill scientist who is leading a government-sponsored study into the treatment.
The antibody therapy Regen-Cov is currently authorised in the US to treat people with mild to moderate Covid-19 and for the prevention of infection in those exposed to the disease, as well as those at high risk of exposure in settings such as nursing homes or prisons.
The study included 842 people who received a placebo and 841 who received the treatment dosed at 1,200 milligrams and injected under the skin.
During a follow-up period of two to eight months, there were seven Covid cases in the treatment group and 38 in the placebo group, representing a risk reduction of 81.6 per cent.
There were no hospital admissions among those in the treatment group, compared to six in the placebo group. No deaths stemming from Covid-19 occurred in either group.
“A single dose of Regen-Cov provided long-term protection against Covid-19, including times of particularly high risk from household exposure and in the longer-term during ongoing broader exposure,” said George Yancopoulos, the company's president and chief scientific officer.
Regeneron said researchers were able to demonstrate the impact of the drug even after the immediate risk of household infection had subsided.
It intends to rapidly share the additional data with regulatory authorities.
Agencies contributed to this report