FDA expands use of COVID-19 antibody cocktail

While the world’s spotlight remains on the race to vaccinate people against COVID-19, the battle to help those who have not been vaccinated or who do not respond fully to the jabs remains fierce.

The FDA has expanded the use of Regeneron’s antibody cocktail, REGEN-COV, updating its emergency use authorisation (EUA) to include those at high risk of developing severe COVID-19 who have been exposed to the virus.

The therapy – a combination of monoclonal antibodies casirivimab and imdevimab – is now the only COVID-19 antibody therapy available in the US for both treatment and post-exposure prophylaxis, says the company.

REGEN-COV is not the only antibody drug on the market. Lilly’s bamlanivimab/etesevimab combo and GSK/Vir’s sotrovimab were approved earlier this year. However, recent trial data may mean Regeneron is pulling ahead in the COVID-19 antibody drug race.

The EUA issued by the FDA covers casirivimab and imdevimab for the treatment of mild to moderate COVID-19 in adults and children 12 years or older who have tested positive for coronavirus and who are at high risk of progressing to severe COVID-19. It applies to those who are not fully vaccinated or who are not expected to mount an adequate response to vaccination.

Regeneron says that people who may not respond fully to COVID-19 vaccination because of immunocompromising conditions or immunosuppressive medicines include those with haematologic cancers, receiving chemotherapy, stem cells or haemodialysis, who have received organ transplants and people taking medications that blunt the immune response.

The expansion of REGEN-COV is based on results from a pivotal phase 3 trial run jointly with the National Institutes of Health that showed the risk of symptomatic infections fell by 81% for those who lived with an infected person. A post-hoc analysis of participants at high risk for progression to severe COVID-19 showed a 76% risk reduction compared to placebo.

The EUA comes less than two months after approval of a more user-friendly subcutaneous injection form of REGEN-COV, removing the need for a more invasive intravenous infusion, and of a lower dose of the Regeneron drug.

In late June, Eli Lilly was dealt a blow when its COVID-19 antibody cocktail was halted in the US due to data showing its combination of drugs was less effective against the gamma variant of SARS-COV-2, which is gaining ground in the US.

REGEN-COV, which is developed and distributed by Roche in Europe, is expected to receive EMA approval later this year.