A combination treatment of two antibodies (casirivimab and imdevimab) is recommended for two specific groups of patients with covid-19 by a panel of international experts and patients of the WHO Guideline Development Group (GDG) of the BMJ today ‘hui.
The former are patients with non-severe covid-19 who have the highest risk of hospitalization and the latter are those with severe or critical covid-19 who are HIV negative because they have not developed their own response in antibody to covid-19.
The first recommendation is based on new evidence from three trials that have not yet been peer-reviewed, but show that casirivimab and imdevimab likely reduce the risk of hospitalization and the duration of symptoms in people with the most severe symptoms. more at risk of serious illness, such as unvaccinated people, the elderly, or immunocompromised patients.
This second recommendation is based on data from the RECOVERY trial showing that casirivimab and imdevimab likely reduce the number of deaths (ranging from 49 fewer per 1,000 in critically ill patients to 87 fewer in critically ill patients. ) and the need for mechanical ventilation in HIV negative patients.
For all other covid-19 patients, the benefits of this antibody therapy are unlikely to be significant.
Casirivimab and imdevimab are monoclonal antibodies which, when used together, bind to the SARS-CoV-2 spike protein, neutralizing the ability of the virus to infect cells.
The recommendations are part of a living guideline, developed by the World Health Organization with methodological support from the MAGIC Evidence Ecosystem Foundation, to provide up-to-date and reliable advice on the management of covid-19 and to help physicians to make better decisions with their patients.
Living guidelines are useful in rapidly evolving areas of research like covid-19, as they allow researchers to update previously verified and peer-reviewed summaries of evidence as new information becomes available.
The panel recognized several cost and resource implications associated with this treatment, which can make it difficult for low- and middle-income countries to access. For example, rapid serologic testing will be needed to identify eligible patients who are critically ill, treatment should be administered intravenously using specialized equipment, and patients should be monitored for allergic reactions.
They also recognize the possibility that new variants will emerge in which the casirivimab and imdevimab antibodies may have a reduced effect.
However, they say, given the demonstrated benefits to patients, “the recommendations should provide a stimulus to engage all possible mechanisms to improve global access to the intervention and associated tests.”
Today’s advice is in addition to previous recommendations for the use of interleukin-6 receptor blockers and systemic corticosteroids for patients with severe or critical covid-19; and against the use of ivermectin and hydroxychloroquine in patients with covid-19 regardless of the severity of the disease.
Rochwerg, B., et al. (2021) A living WHO guideline on drugs for covid-19. BMJ. doi.org/10.1136/bmj.m3379.