Casirivimab + Imdevimab

by Douglas Black, Pharm.D. last updated 2020-11-24 13:05:15.937578-05:00 © Antimicrobial Therapy, Inc.
  • Casirivimab and Imdevimab (Regeneron) are two monoclonal antibodies that were designed to specifically block two areas of the 'Spike Protein' of SARS-CoV-2  and, hence, infectivity of the virus. It is a combination product containing both antibodies.
  • The FDA issued an Emergency Use Authorization (EUA) letter on 21 Nov 2020 for treatment of mild to moderate COVID-19 in adults and children (age ≥12 years, wt ≥40 kg) who are at risk of progression to severe disease and/or hospitalization.
  • Combination (Casirivimab 1200 mg + Imdevimab 1200 mg) administered together as a single IV infusion.
  • Administer in 250 mL of normal saline over one hour through an IV line with a 0.2 micron polyethersulfone filter (withdraw 20 mL from the bag, then add each antibody).
  • Administer the diluted infusion solution immediately. If this is not possible, the diluted solution may be stored in the refrigerator (2-8ºC) for up to 36 hours, or at room temperature (25ºC) for up to four hours (including infusion time).
  • Age ≥12 years, weight ≥40 kg: same as adult dose.
  • No adjustment recommended.
  • The effect of hepatic impairment on the pharmacokinetics of casirivimab and imdevimab is unknown.
  • Monitor patients during infusion and for at least one hour after infusion is complete.
  • Infusion-related adverse effects:
    • Fever, chills, nausea, headache, bronchospasm, hypotension, angioedema, throat irritation, rash including urticaria, pruritus, myalgia, dizziness.
  • Serious hypersensitivity reaction, including anaphylaxis.
  Casirivimab Imdevimab
 Class IgG1 mAb IgG1 mAb
PK/PD Index No data No data
Pharmaceutical
Preparation
Injection Injection
Usual Dose  1200 mg 1200 mg
Pregnancy
Category
No human data No human data
Food Effect1 Not applicable Not applicable
Oral
Absorption2 (%)
Not applicable Not applicable
Mean Serum Level3
(μg/mL)
No data No data
Protein Binding
(%)
No data No data
Average Serum
Half-life4
Approx 24 hrs Approx 24 hrs
Biliary Penetration5 (%) No data No data
CSF/Blood
Penetration6 (%)
No data No data
Therapeutic Levels in CSF7 No data No data
Volume of Distribution8
(Vd)
No data No data
AUC
(μg*DAY/mL)
No data No data
CYP450, Transporter
Interactions
 No known interactions No known interactions
  • Notes:
    • 1 Adult preparations unless otherwise noted.
    • 2 Absorption under optimal conditions.
    • 3 Total drug; adjust for protein binding to determine free drug concentration.
      • SD = after single dose
      • SS = steady state after multiple doses
    • 4 Assumes CrCl > 80 mL/min
    • 5 Peak concentration in bile/peak concentration in serum x 100
    • 6 CSF levels with inflammation
    • 7 Judgment based on drug dose & organism susceptibility. CSF concentration ideally ≥10x above MIC.
    • 8 Volume of Distribution (Vd):
      • V/F = Vd/oral bioavailability
      • Vss = Vd at steady state
  • No clinically significant interactions known.
  • Product availability (both antibodies): 300 mg and 1332 mg vials, 120 mg/mL, preservative free.
  • Storage: refrigerate unopened vials at 2-8ºC, protected from light. Allow to equilibrate to room temperature for 20 minutes before preparation. Do not expose to direct heat.