US-based Regeneron Pharmaceuticals Inc said on Tuesday initial data from a continuing study of its experimental antibody cocktail for use in some hospitalised Covid-19 patients demonstrated the therapy was sufficiently effective to necessitate continuing the trial.
The company is testing the therapy, a combination of two antibodies — casirivimab and imdevimab — in hospitalised patients requiring low-flow oxygen.
The drugmaker said in September the cocktail reduced viral levels and improved symptoms in non-hospitalised Covid-19 patients.
Study participants included those who produced an effective immune response on their own (seropositive), and those whose immune response was not yet adequate (seronegative).
Seronegative patients treated with the antibody cocktail had a lower risk of death or needing mechanical ventilation, the company said.
Based on these results, the company said an ongoing late-stage study in hospitalised patients will continue.
The US Food and Drug Administration (FDA) last month issued emergency use authorisation for the antibody therapy for use in mild to moderate Covid-19 patients who are not currently hospitalised.
The antibody cocktail — casirivimab and imdevimab — administered together (formerly known as REGN-COV2 or REGEN-COV2), a therapy currently being investigated for use in Covid-19, has received emergency use authorisation (EUA) from the FDA. Casirivimab and imdevimab administered together are authorised for the treatment of mild to moderate Covid-19 in adults, as well as in pediatric patients at least 12 years of age and weighing at least 40 kg, who have received positive results of direct SARS-CoV-2 viral testing and are at high risk for progressing to severe Covid-19 and/or hospitalisation. The clinical evidence from Regeneron's outpatient trial suggests that monoclonal antibodies such as casirivimab and imdevimab have the greatest benefit when given early after diagnosis and in patients who have not yet mounted their own immune response or who have high viral load.