COVID-19 Neutralizing Antibody (Casirivimab-Imdevimab, Sotrovimab) Orders

NOTE: supply of these medications can vary week to week and facility to facility. It is important to follow local updates about medication availability and the latest recommendations for preferred medications.


Sotrovimab 500 mg by injection has at times been considered appropriate for the treatment of COVID-19 patients with mild to moderate symptoms when administered by intravenous infusion within 5 days of symptom onset. With evidence of little impact for Omicron and related variants, its use is not currently supported. Sotrovimab use is restricted and must comply with current guidelines. There is a dependency on laboratory capacity for the determination of variants which is itself subject to change. Please use the resource links below for access to current guidelines.

Clinical Requirements

  • Outpatients or inpatients admitted for non-COVID-19 reasons or inpatients with hospital-acquired COVID-19 if meeting ALL of the following 4 criteria:

    1. Mild to moderate COVID-19 symptoms

    2. Positive COVID-19 PCR test result

    3. Able to receive treatment within 5 days of symptom onset

    4. Confirmed not infected with BA.2 variant of SARS-CoV-2


  • Meet 1 of the following 2 criteria:

    1. Unvaccinated (no COVID-19 immunization) AND one or more of:

        • Age 55 and over

        • Age 18 and over with at least 1 of the following comorbidities:

          • Diabetes requiring medication

          • Obesity with BMI > 30 kg/m2

          • Chronic Kidney Disease (eGFR 60 ml/min/1.73 m2)

          • Congestive Heart Failure (NYHA class II, III or IV)

          • COPD

          • Moderate to severe asthma

          • Pregnancy

    2. Immunocompromised regardless of immunization status

      • Transplant (solid organ or stem cell) recipients

      • Oncology patients receiving any chemotherapy or immunosuppressive therapy since December 2020

      • Inflammatory conditions (e.g., RA, Lupus, IBD, etc.) receiving any systemic immunosuppression since December 2020



Casirivimab-Imdevimab ("REGEN-COV", single 4000/4000 mg dose) may be used to treat hospitalized patients aged 12 years or older weighing at least 40 kg with acute laboratory-confirmed COVID-19, if specific conditions are met. However, this agent fails to neutralize the Omicron variant of SARS-CoV-2 and should not be used for confirmed or suspected Omicron variants or sub-variants.

Clinical Requirements

  • COVID-19 naive (no prior COVID-19 disease), meeting all of the following criteria:

    1. No documented history of prior COVID-19 infection

    2. No prior treatment with a COVID-19 neutralizing antibody (except bamlanivimab monotherapy)

    3. No prior COVID-19 vaccination unless within 14 days of a first dose

    4. Seronegative, based on results from a laboratory-based or rapid serology test

  • Immunocompromised, as defined by any of the following:

    1. Congenital and acquired immunodeficiency, including severe combined immunodeficiency (SCID) and profound hypogammaglobulinemia

    2. HIV infection with CD4 T lymphocyte count <200 (or less than 15%) and unsuppressed viral load

      • Pediatrics: 5 years or older – use CD4 count <200

    3. Any haemotological malignancy

    4. Within 24 months of stem cell transplant

    5. Solid organ transplant

    6. Current receipt of prednisone >20 mg/day (or equivalent) for more than 14 days

      • Pediatrics: >2 mg/kg body weight for more than 14 days

    7. Chimeric antigen receptor (CAR) T-cell therapy

      • Anti-B cell therapy (current or within last 6 months), e.g., ocrelizumab, rituximab

Research Requirements

  • Inpatients admitted for non-COVID reasons with nosocomial COVID-19 infection and enrolled in the CATCO-NOS clinical trial (1200/1200 mg dose).