The FDA on Wednesday granted an emergency-use authorisation (EUA) to GlaxoSmithKline and Vir Biotechnology's sotrovimab for adults and paediatric patients ages 12 and older who have mild-to-moderate COVID-19 and are at high risk of progressing to severe disease. "With the authorisation of this monoclonal antibody treatment, we are providing another option to help keep high-risk patients with COVID-19 out of the hospital," commented Patrizia Cavazzoni, director of the FDA's Center for Drug Evaluation and Research. The companies said sotrovimab will be available in the US in the coming weeks

The FDA decision was based an interim analysis from the Phase III COMET-ICE trial, which evaluated sotrovimab monotherapy for the early treatment of COVID-19 in adults at high risk of hospitalisation. Data from 583 patients showed an 85% reduction in hospitalisation for more than 24 hours or death in those given an infusion of the antibody therapy compared to placebo, achieving the study's primary endpoint.

An analysis at day 29 for the entire COMET-ICE population is expected as early as the first half of 2021. GlaxoSmithKline and Vir added that they plan to submit an application seeking full FDA approval of sotrovimab in the second half of 2021.

Still potent against circulating variants

Meanwhile, the FDA said it is monitoring circulating variants and their sensitivity to currently authorised monoclonal antibodies, with laboratory tests so far indicating that sotrovimab retains activity against SARS-CoV-2 strains first reported in the UK (B.1.1.7), South Africa (B.1.351), Brazil (P.1), California (B.1.427/B.1.429), New York (B.1.526) and India (B.1.617).

Hal Barron, president of R&D at GlaxoSmithKline, said that despite the fast pace of COVID-19 vaccinations in the US, "there is still a need to help prevent infected patients from developing complications." He noted that "in just over a year since starting our collaboration and in less than 10 months since beginning clinical trials, we are delighted that…the benefits of this unique monoclonal antibody will now be available to patients in need."

Sotrovimab, also known as VIR-7831, targets a conserved epitope of the SARS-CoV-2 spike protein, which the companies say is less likely to mutate over time. The antibody is also being evaluated under a rolling review by the European Medicines Agency, whose Committee for Medicinal Products for Human Use (CHMP) recently recommended that the antibody therapy be approved for at-risk COVID-19 patients 12 years and older.

Meanwhile, results from the Phase II BLAZE-4 trial demonstrated that the combination of sotrovimab and Eli Lilly's bamlanivimab cut viral loads more than placebo in low-risk adults with COVID-19. The US pulled its authorisation of bamlanivimab monotherapy last month because of concerns it may not be able to neutralise some variants circulating in the US. It is now only being supplied in the country as part of an antibody cocktail co-administered with etesevimab.