Casirivimab and Imdevimab

KEY POINTS

• Casirivimab (REGN10933) and imdevimab (REGN10987) are recombinant human IgG1 monoclonal antibodies that target the receptor binding domain of the spike protein of SARS-CoV-2, which can reduce viral replication
  • Monoclonal antibodies are molecules engineered to serve as substitute antibodies that can restore, enhance or mimic the immune system’s attack on cells
  • Is a form of passive immunity
  • The ending of the name “vi” is for targeting viruses and “mab” stands for monoclonal antibody
• Casirivimab and imdevimab are given together, neither is FDA-approved for any indication either alone or in combination
• This medication is produced by Regeneron Pharmaceuticals and was given to U.S. President Donald Trump when he had COVID-19
  • It may reduce the need for hospitalization or emergency department visit when given in accordance with EUA criteria. Clinical data are provided in the Fact Sheet.
• Was given Emergency Use Authorization (EUA) status from the FDA on 22 November 2020
  • EUA covers use by healthcare providers in an outpatient settings to treat mild to moderate COVID-19 in adults and pediatric patients with positive results of direct SARS-CoV-2 viral testing who are 12 years of age and older weighing at least 40 kg, and who are at high risk for progressing to severe COVID-19 and/or hospitalization
    • There is a long, broad list of criteria for what is considered “high risk”
    • Use an “outpatient” infusion sites is likely to be challenging from an infection control standpoint and overall logistics standpoint
    • Use later in disease may lead to worse outcomes, is recommended to give within 10 days of symptom onset
  • Not authorized to be given to:
    • Adults or pediatric patients who are hospitalized due to COVID-19
    • Adults or pediatric patients who require oxygen therapy due to COVID-19
    • Adults or pediatric patients who require an increase in baseline oxygen flow rate due to COVID-19 in those patients on chronic oxygen therapy due to underlying non-COVID-19-related comorbidity
• Dosage is 1,200 mg of casirivimab and 1,200 mg of imdevimab administered together as a single 250 mL infusion diluted in 0.9% NS given over at least 60 minutes via pump or gravity
  • Infusion should be followed by a 1 hour observation period to monitor for adverse drug reactions
  • No dose adjustment for renal function, effect of hepatic dysfunction is unknown
• Casirivimab and imdevimab come in separate solutions that must be diluted prior to administration
  • Unopened vials require storage under refrigeration
    • Both products come in two vial sizes (2.5 mL and 11.1 mL)
  • Final 250 mL solution for infusion should be used within 36 hours if refrigerated and within 4 hours if kept at room temperature, including infusion time
• Adverse events may occur
  • Beware infusion-related reactions (fever, chills, nausea, headache, bronchospasm, hypotension, angioedema, throat irritation, rash including urticaria, pruritus, myalgia, dizziness)
  • Beware anaphylaxis and allergic reactions, one was reported to occur in the trial
    • Began within 1 hour of completing the infusion and required treatment with epinephrine
  • Adverse events reported as Grade 3 or 4 in the clinical trial with these drugs were pneumonia, hyperglycemia, nausea and vomiting (2,400 mg casirivimab and imdevimab), intestinal obstruction and dyspnea (8,000 mg casirivimab and imdevimab)
• Adverse reactions are to be reported to FDA Medwatch & Regeneron Pharmaceuticals
• Patient must be provided with the “Fact Sheet for Patients, Parents and Caregivers” and be agreeable to the therapy
• Drug-drug interactions are suspected to be unlikely