Know When to Refer Patients for New COVID-19 Monoclonal Antibodies

Bamlanivimab and casirivimab/imdevimab will be the first meds authorized to treat OUTPATIENTS with COVID-19.

These new monoclonal antibodies block SARS-CoV-2 from entering cells. Both meds are single-dose IV infusions given over 1 hour.

They're being given at many locations, such as infusion centers...pop-up sites (tents, etc)...long-term care...or even patients' homes.

Evidence suggests bamlanivimab or casirivimab/imdevimab may reduce ED or hospital visits by about 5% in outpatients with mild to moderate COVID-19...who are at high risk of progressing to severe illness.

But this is based on PRELIMINARY data...with very few patients needing ED or hospital care in either the antibody or placebo group.

So far, these meds seem well tolerated. But rare hypersensitivity reactions can occur...so monitoring is needed for 1 hour afterward.

Point out that these new "mabs" are NOT for all outpatients with COVID-19. Be familiar with emergency use authorization (EUA) criteria.

Patients must have a positive COVID-19 test and be within 10 days of symptom onset...be age 12 or older...and weigh at least 40 kg.

Then consider if patients are at high risk of serious COVID-19 complications...such as age 65 or older, BMI 35 or higher, diabetes, etc.

Expect even more stringent criteria if local supply is tight.

But be aware, patients CANNOT have increased oxygen needs due to COVID-19...evidence suggests these meds may be harmful in this case.

If patients qualify and want treatment, refer them ASAP. Explain that these meds seem to work best when given early...and COVID-19 often starts with mild symptoms, but can quickly get worse.

Clarify that patients don't currently have to pay for the meds...and many payers will cover the cost of the infusion.

Reinforce that patients still need to self-isolate after getting these meds. They aren't a cure and don't prevent spread of infection.

Advise deferring COVID-19 vaccination for at least 90 days after these "mabs"...since they may interfere with the vaccine immune response.

Check with your health dept on where to refer patients...or go to the Health and Human Services "Protect Public Data Hub" website.

Get more specifics on the criteria for using these monoclonal antibodies in our chart, Treatments of Interest for COVID-19.

Key References

  • N Engl J Med Published online Oct 28, 2020; doi:10.1056/NEJMoa2029849
  • www.fda.gov/media/143603/download (12-17-20)
  • www.fda.gov/media/143892/download (12-17-20)
Pharmacist's Letter. January 2021, No. 370104



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