WHO updates guidance on monoclonal antibody treatment for COVID-19

A WHO guideline panel has updated recommendations for monoclonal antibody treatment in its “living” guide on drugs for COVID-19. The guidelines are published in The BMJ.

The panel now recommends a combination of casirivimab and imdevimab (REGEN-COV; Regeneron) for patients with non-severe COVID-19 at high risk for hospitalization and patients with severe or critical COVID-19 who are seronegative.

The new update is the fifth revision WHO has made to its treatment guide.

“Casirivimab/imdevimab is unlikely to be available for all individuals who would choose to receive treatment, supporting the recommendation to reserve them for those at highest risk of hospitalization,” Bram Rochwerg, MSc, MD, FRCPC, an intensivist and researcher at McMaster University in Canada, and colleagues wrote.

Results from several randomized trials, including the RECOVERY trial, prompted the new recommendations, according to the panel.
The first recommendation regarding patients with non-severe COVID-19 only applies to adults. While the panel “had no reason to think that children with COVID-19 would respond any differently,” due to a lack of evidence, they did not recommend the combination regimen for children with non-severe COVID-19.

The second recommendation regarding patients with severe or critical illness “reflects the likelihood that any benefits are restricted to patients who have seronegative status,” Rochwerg and colleagues wrote.

In the RECOVERY trial, seronegative patients who received the combination treatment were less likely to need mechanical ventilation (42 fewer patients per 1,000; 95% CI, 74-6), according to the panel. The trial enrolled only adults, so the recommendation for children with severe or critical illness who are seronegative “is currently uncertain,” the panel wrote. However, it noted that children who are seronegative with COVID-19 “may benefit from casirivimab/imdevimab.”

Healio Primary Care previously reported on what researchers described as the largest comparative randomized trial of monoclonal antibody treatments for COVID-19. In the OPTIMISE-C19 trial, Erin McCreary, PharmD, an infectious disease pharmacist and clinical assistant professor of medicine at the University of Pittsburgh School of Medicine, and colleagues found that bamlanivimab/etesevimab (Eli Lilly & Co.) and casirivimab/imdevimab were safe and appeared to be equally effective in patients with mild to moderate COVID-19.

Casirivimab/imdevimab received an emergency use authorization from the FDA in November 2020. The FDA issued the EUA after reviewing trial data that found only 3% of patients receiving the treatment became hospitalized or visited the ED compared with 6% of patients receiving placebo.

In the living guide on COVID-19 drugs, the WHO panel also strongly recommended using interleukin-6 receptor blockers and systemic corticosteroids for patients with severe or critical COVID-19, while strongly advising against the use of ivermectin and hydroxychloroquine in patients with COVID-19, regardless of disease severity, outside of a clinical trial setting.