An experimental arthritis drug could help prevent severe Covid-19 in those at highest risk from the disease, research suggests.
Otilimab demonstrated a potential clinical benefit in people aged between 70 and 80 over and above the current standard of care, the study indicated.
However, younger, lower risk patients did not benefit from the drug, said pharmaceutical company GlaxoSmithKline (GSK), which is running the trial.
Based on these results, the study is expanding the cohort of patients aged 70 and older.
A further 350 people in this age group will be enrolled, and results are expected in the second half of this year.
The aim of the Oscar (Otilimab in severe covid-19 related disease) study is to assess the effectiveness of otilimab in treating severe lung disease associated with Covid-19 infection.
Results from the phase two proof of concept study found that patients of all ages showed a treatment difference of 5.3%, but this did not reach statistical significance.
However, a pre-planned efficacy analysis by age in patients aged 70 and older (180 patients out of 806) showed that 65.1% were alive and free of respiratory failure 28 days after treatment with otilimab plus standard of care (including anti-viral treatments and corticosteroids).
This compared with 45.9% of patients who received the standard of care alone.
In a mortality analysis up to day 60, researchers found a treatment difference of 14.4% in favour of otilimab, with rates of 40.4% on standard of care and 26% on otilimab plus standard of care in patients 70 years and older.
Study participants were enrolled at 130 sites around the world, including in the US, Europe, Asia, Russia, South Africa and South America, and at hospitals in Manchester and Liverpool.
Christopher Corsico, senior vice president development at GSK, said: “Patients aged 70 and over account for 70% of Covid-related deaths and nearly 40% of hospitalisations.
“Given the profound impact this pandemic is having on the elderly and the encouraging data we are sharing today, we are hopeful this finding will be replicated in the additional cohort.”
Otilimab is a fully human monoclonal antibody that inhibits granulocytemacrophage colony-stimulating factor (GM-CSF), a protein that plays a central role in a broad range of immune-mediated diseases, including rheumatoid arthritis.
GM-CSF acts on cells, including an immune cell type that plays a key role in the inflammatory process, leading to inflammation, joint damage and pain.