IDSA Updates Guidelines on Neutralizing Antibodies for COVID-19

The Infectious Diseases Society of America (IDSA) has updated its treatment guidelines for utilizing neutralizing antibodies. The expanded guidelines looks at this form of treatment based upon newly available literature and approvals. IDSA reported the updates would be integrated on the website, but they did provide the information on their site for immediate clinical use. The updated guidelines can be found here.

Neutralizing antibodies have been through many fluctuations including promising treatment early on before new COVID-19 mutations, to the last of the authorized antibody treatments, bebtelovimab, rendered ineffective against COVID-19 and its emergency use authorization (EUA) withdrawn at the end of November. Bebtelovimab was the sixth previously authorized antibody withdrawn for treatment and seemed to dimmer the remaining hope of the use of this treatment for the virus.

It is important to note, tixagevimab and cilgavimab (evusheld) remains FDA authorized for prevention; although an FDA statement earlier this month said the agency anticipated that Evusheld would not effectively neutralize the Omicron variant, XBB15.

In the earlier days of the pandemic and in the vital interest of public health, the FDA provided EUAs to multiple antibody therapies for COVID-19 treatment. As new variants emerged, the efficacy of these treatments waned leaving the FDA with no choice but to withdraw EUAs for each of them.

The authors of the IDSA guideline point out that the recommendation for the use of neutralizing antibodies for COVID-19 treatment was replaced with a statement about in vitro resistance to circulating strains in the US.

“During 2022, multiple Omicron sub-variants with progressively greater in vitro reductions in susceptibility to multiple anti-SARS CoV-2 neutralizing antibodies emerged,” the statement read. The authors of the statement acknowledged the last antibody having its authorization withdrawn, but pointed to the possibility they may become a therapeutic option again as new variants emerge.

“Although the general trend has been towards increasing resistance to therapeutic neutralizing monoclonal antibodies, there have been instances in which new variants became more susceptible to existing anti-SARS CoV-2 neutralizing antibodies. Should this occur again, or should newly developed, more active neutralizing antibodies be authorized for treatment, the panel will offer recommendations regarding use,” the statement read.

For the preexposure and postexposure prophylaxis portion of the guidelines, IDSA recommended evusheld as a potential option in other parts of the world where the circulating variants may still be susceptible to it.

“For areas of the world where predominant regional variants are susceptible to the agent, in moderately or severely immunocompromised individuals, the IDSA guideline panel suggests pre-exposure prophylaxis with tixagevimab/cilgavimab rather than no tixagevimab/cilgavimab for patients for whom vaccination is not likely to be adequate or is not possible,” the IDSA recommendation read.

The IDSA offered detailed information for the guideline to help clinicians identify the appropriate patients in the appropriate settings.

This IDSA update was endorsed by the Society for Healthcare Epidemiology of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists.