GlobalHealth Threats

6 August: Results of a study giving REGEN-COV antibody treatment to prevent post-exposure COVID-19 infection has been published in the New England Journal of Medicine. Over 1,500 household contacts 12 years and older of COVID-19 patients were included. Within 96 hours of their household contact testing positive, they were given either REGEN-COV or a placebo by subcutaneous (under the skin) injection. There were 11 COVID-19 infections out of 753 people who received the treatment, compared to 59 cases in the 752 people who received placebo. This equates to a 66% reduction in risk of infection, and an 81% reduction for symptomatic infection. People treated with REGEN-COV experienced symptoms for an average of 2 weeks less than the placebo group (1.2 weeks and 3.2 weeks respectively). In addition, the REGEN-COV treatment group had high levels of virus for a shorter period.

REGEN-COV treatment was approved by the FDA for post exposure prevention of COVID-19 this week.

13 April: Data from a phase 3 trial, released by pharmaceutical company Regeneron, showed treatment (REGEN-COV = casirivimab with imdevimab) reduced the risk and burden of COVID-19 infection among household contacts infected of SARS-CoV-2. The trial, which was jointly run with the National Institute of Allergy and Infectious Diseases (NIAID) and part of the National Institutes of Health (NIH), enrolled 1,505 people who were not infected with SARS-CoV-2 at baseline and randomized them to either received REGEN COV or not. They then “assessed the effect of REGEN-COV on uninfected individuals without anti-SARS-CoV-2 antibodies or any COVID-19 symptoms, who lived in the same household as an individual who tested positive for SARS-CoV-2 within the prior 4 days.”

Researchers found REGEN-COV rapidly protected household contacts with 72% protection against symptomatic infections in the first week, and 93% in subsequent weeks – with an overall risk reduction of 81%.

Those who developed symptoms cleared the virus faster and had much shorter symptom duration. Limitations of the study included "Benefit of treatment with REGEN-COV has not been observed in patients hospitalized due to COVID-19. Monoclonal antibodies, such as REGEN-COV, may be associated with worse clinical outcomes when administered to hospitalized patients with COVID-19 requiring high flow oxygen or mechanical ventilation."

Regeneron are in discussions with the U.S. FDA regarding an EUA expansion to include treatments.