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Regen-Cov Dosage

Generic name: Casirivimab 300mg in 2.5mL
Dosage form: injection
Drug class: Antiviral combinations

Medically reviewed by Drugs.com. Last updated on Mar 27, 2024.

Patient Selection

The optimal dosing regimen for treatment of COVID-19 has not yet been established.

The recommended dosing regimen may be updated as data from clinical trials become available.

Patient Selection for Treatment and Post-Exposure Prophylaxis

Treatment:

This section provides essential information on the unapproved product, REGEN-COV (casirivimab and imdevimab) co-formulated product and REGEN-COV (casirivimab and imdevimab) supplied as individual vials to be administered together, for the treatment of adult and pediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death.

Post-Exposure Prophylaxis:

This section provides essential information on the unapproved product, REGEN-COV (casirivimab and imdevimab) co-formulated product and REGEN-COV (casirivimab and imdevimab) supplied in individual vials to be administered together, in adult and pediatric individuals (12 years of age and older weighing at least 40 kg) for the post-exposure prophylaxis of COVID-19 in individuals who are at high risk for progression to severe COVID-19, including hospitalization or death, and are:

  • not fully vaccinated or who are not expected to mount an adequate immune response to complete SARS-CoV-2 vaccination (for example, individuals with immunocompromising conditions including those taking immunosuppressive medications) and
    -
    have been exposed to an individual infected with SARS-CoV-2 consistent with close contact criteria per Centers for Disease Control and Prevention (CDC) or
    -
    who are at high risk of exposure to an individual infected with SARS-CoV-2 because of occurrence of SARS-CoV-2 infection in other individuals in the same institutional setting (for example, nursing homes, prisons).

The following medical conditions or other factors may place adults and pediatric patients (age 12-17 years and weighing at least 40 kg) at higher risk for progression to severe COVID-19:

  • Older age (for example, age ≥65 years of age)
  • Obesity or being overweight (for example, BMI >25 kg/m2, or if age 12-17, have BMI ≥85th percentile for their age and gender based on CDC growth charts, https://www.cdc.gov/growthcharts/clinical_charts.htm)
  • Pregnancy
  • Chronic kidney disease
  • Diabetes
  • Immunosuppressive disease or immunosuppressive treatment
  • Cardiovascular disease (including congenital heart disease) or hypertension
  • Chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension)
  • Sickle cell disease
  • Neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies)
  • Having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation (not related to COVID-19))

Other medical conditions or factors (for example, race or ethnicity) may also place individual patients at high risk for progression to severe COVID-19 and authorization of REGEN-COV under the EUA is not limited to the medical conditions or factors listed above.

For additional information on medical conditions and factors associated with increased risk for progression to severe COVID-19, see the CDC website: https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html. Healthcare providers should consider the benefit-risk for an individual patient.

Dosage

Treatment:

The dosage in adult and pediatric patients (12 years of age and older weighing at least 40 kg) is 600 mg of casirivimab and 600 mg of imdevimab administered together as a single intravenous infusion or by subcutaneous injection. Casirivimab and imdevimab should be given together as soon as possible after a positive viral test for SARS-CoV-2 and within 10 days of symptom onset.

Post-Exposure Prophylaxis:

The dosage in adult and pediatric individuals (12 years of age and older weighing at least 40 kg) is 600 mg of casirivimab and 600 mg of imdevimab administered by subcutaneous injection or together as a single intravenous infusion. Casirivimab and imdevimab should be given together as soon as possible following exposure to SARS-CoV-2.

For individuals whom repeat dosing is determined to be appropriate for ongoing exposure to SARS-CoV-2 for longer than 4 weeks and who are not expected to mount an adequate immune response to complete SARS-CoV-2 vaccination, the initial dose is 600 mg of casirivimab and 600 mg of imdevimab by subcutaneous injection or intravenous infusion followed by subsequent repeat dosing of 300 mg of casirivimab and 300 mg of imdevimab by subcutaneous injection or intravenous infusion once every 4 weeks for the duration of ongoing exposure.

For Intravenous Infusion:

  • Casirivimab and imdevimab solution co-formulated in a vial and in individual vials, including co-packaged carton and dose pack, must be diluted prior to intravenous administration.
  • Administer casirivimab and imdevimab together as a single intravenous infusion via pump or gravity (see Table 1, Table 2, Table 3 and Table 4).
  • Clinically monitor patients during infusion and observe patients for at least 1 hour after infusion is complete.

For Subcutaneous Injection:

  • Administer casirivimab and imdevimab using the co-formulated vial or using the individual vials by subcutaneous injection (see Table 5 and Table 6).
  • Clinically monitor patients after injections and observe patients for at least 1hour.

Dose Adjustment in Specific Populations

Pregnancy or Lactation

No dosage adjustment is recommended in pregnant or lactating women.

Pediatric Use

No dosage adjustment is recommended in pediatric patients who weigh at least 40 kg and are older than 12 years of age. REGEN-COV (casirivimab and imdevimab) is not recommended for pediatric patients weighing less than 40 kg or those less than 12 years of age.

Renal Impairment

No dosage adjustment is recommended in patients with renal impairment.

Dose Preparation and Administration

There are TWO different formulations of REGEN-COV:

  • Casirivimab and imdevimab co-formulated solution containing two antibodies in a 1:1 ratio in a vial.
  • Casirivimab and imdevimab available as individual antibody solutions in separate vials supplied as follows:
    • Individual vials in individual cartons, or
    • together in a single carton (also referred to as a co-packaged carton), or
    • in a dose pack. The dose pack contains individual vials of casirivimab and imdevimab, configurations that may vary in vial size, strength and appearance and are available in dose pack configurations that include 2, 5, and 8 cartons.

For treatment, intravenous infusion is strongly recommended. Subcutaneous injection is an alternative route of administration when intravenous infusion is not feasible and would lead to delay in treatment.

For post-exposure prophylaxis, either subcutaneous injection or intravenous infusion can be used.

There are differences in the way the two formulations are prepared. Carefully follow the preparation procedures below.

  • Casirivimab and imdevimab co-formulated solution in a vial and casirivimab or imdevimab as individual antibody solutions in separate 11.1 mL vials may be used to prepare more than one dose simultaneously as appropriate, either in intravenous bags or in syringes for subcutaneous injection. Discard any product remaining in the vial.
  • Store unopened casirivimab and imdevimab vials in a refrigerator at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Unopened vials may be stored in the original carton at room temperature [up to 25°C (77°F)] and must be used within 30 days. If not used in the 30 days, discard vials.

Under the EUA, a single-dose vial may be used to prepare more than one dose.

Preparation for Intravenous Infusion

For treatment, the preferred route of administration for casirivimab and imdevimab is by intravenous infusion after dilution.

Casirivimab and imdevimab solution for intravenous infusion should be prepared by a qualified healthcare professional using aseptic technique:

  1. Remove the casirivimab and imdevimab vials from refrigerated storage and allow to equilibrate to room temperature for approximately 20 minutes before preparation. Do not expose to direct heat. Do not shake the vials.
  2. Inspect casirivimab and imdevimab vials visually for particulate matter and discoloration prior to administration. Should either be observed, the vial must be discarded and replaced with a new vial.
    • The solution for each vial should be clear to slightly opalescent, colorless to pale yellow.
  3. Obtain a prefilled intravenous infusion bag containing either 50 mL, 100 mL, 150 mL, or 250 mL of either 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP.
  4. Withdraw the appropriate amount of casirivimab and imdevimab from each respective vial(s) and inject into a prefilled infusion bag containing either 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP, (see Table 1 and Table 2). If using one vial to prepare more than one infusion bag, then prepare all infusion bags at the same time. The product is preservative-free, therefore do not store unused solution in vial(s).
  5. Gently invert infusion bag by hand approximately 10 times to mix. Do not shake.
  6. This product is preservative-free and therefore, the diluted infusion solution should be administered immediately (see Table 3 and Table 4).
    • If immediate administration is not possible, store the diluted casirivimab and imdevimab infusion solution in the refrigerator between 2°C to 8°C (36°F to 46°F) for no more than 36 hours or at room temperature up to 25°C (77°F) for no more than 4 hours. If refrigerated, allow the infusion solution to equilibrate to room temperature for approximately 30 minutes prior to administration.
Table 1: Recommended Dilution Instructions for 600 mg of Casirivimab and 600 mg of Imdevimab for Intravenous Infusion
Size of Prefilled 0.9% Sodium Chloride or 5% Dextrose Infusion Bag Preparing Using Co-Formulated Casirivimab and Imdevimab Vial Preparing Casirivimab and Imdevimab Using Individual Vials*
*
600 mg of casirivimab and 600 mg of imdevimab are added to the same infusion bag and administered together as a single intravenous infusion.
50 mL Add 10 mL of co-formulated casirivimab and imdevimab (1 vial) into a prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag and administer as instructed below Add:
  • 5 mL of casirivimab (may use 2 vials of 2.5 mL OR 1 vial of 11.1 mL) and
  • 5 mL of imdevimab (may use 2 vials of 2.5 mL OR 1 vial of 11.1 mL)
and inject into a prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag and administer as instructed below
100 mL
150 mL
250 mL
Table 2: Recommended Dilution Instructions for 300 mg of Casirivimab and 300 mg of Imdevimab for Intravenous Infusion for Repeat Dosing*
Size of Prefilled 0.9% Sodium Chloride or 5% Dextrose Infusion Bag Preparing Using Co-Formulated Casirivimab and Imdevimab Vial Preparing Casirivimab and Imdevimab Using Individual Vials†
*
Subsequent repeat dosing every 4 weeks after initial 600 mg casirivimab and 600 mg imdevimab dosing for the duration of ongoing exposure.
†
300 mg of casirivimab and 300 mg of imdevimab are added to the same infusion bag and administered together as a single intravenous infusion.
50 mL Add 5 mL of co-formulated casirivimab and imdevimab into a prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag and administer as instructed below Add:
  • 2.5 mL of casirivimab (may use 1 vial of 2.5 mL OR 1 vial of 11.1 mL) and
  • 2.5 mL of imdevimab (may use 1 vial of 2.5 mL OR 1 vial of 11.1 mL)
and inject into a prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag and administer as instructed below
100 mL
150 mL
250 mL

Administration by Intravenous Infusion

Casirivimab and imdevimab infusion solution should be administered by a qualified healthcare professional using aseptic technique.

  • Gather the recommended materials for infusion:
    • Polyvinyl chloride (PVC), polyethylene (PE)-lined PVC, or polyurethane (PU) infusion set
    • In-line or add-on 0.2 micron polyethersulfone (PES) filter
  • Attach the infusion set to the intravenous bag.
  • Prime the infusion set.
  • Administer the entire infusion solution in the bag via pump or gravity through an intravenous line containing a sterile, in-line or add-on 0.2-micron polyethersulfone (PES) filter (see Table 3 and Table 4). Due to potential overfill of prefilled saline bags, the entire infusion solution in the bag should be administered to avoid underdosage.
  • The prepared infusion solution should not be administered simultaneously with any other medication. The compatibility of casirivimab and imdevimab injection with intravenous solutions and medications other than 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP is not known.
  • After infusion is complete, flush the tubing with either 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP to ensure delivery of the required dose.
  • Discard unused product.
  • Clinically monitor patients during administration and observe patients for at least 1 hour after infusion is complete.
Table 3: Recommended Administration Rate for 600 mg of Casirivimab and 600 mg of Imdevimab for Intravenous Infusion
Size of Prefilled 0.9% Sodium Chloride or 5% Dextrose Infusion Bag used Maximum Infusion Rate Minimum Infusion Time
*
The minimum infusion time for patients administered casirivimab and imdevimab together using the 50 mL prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag must be at least 20 minutes to ensure safe use.
50 mL* 180 mL/hr 20 minutes
100 mL 310 mL/hr 21 minutes
150 mL 310 mL/hr 31 minutes
250 mL 310 mL/hr 50 minutes
Table 4: Recommended Administration Rate for 300 mg of Casirivimab and 300 mg of Imdevimab for Intravenous Infusion for Repeat Dosing*
Size of Prefilled 0.9% Sodium Chloride or 5% Dextrose Infusion Bag used Maximum Infusion Rate Minimum Infusion Time
*
Subsequent repeat dosing every 4 weeks after initial 600 mg casirivimab and 600 mg imdevimab dosing for the duration of ongoing exposure.
†
The minimum infusion time for patients administered casirivimab and imdevimab together using the 50 mL prefilled 0.9% Sodium Chloride or 5% Dextrose infusion bag must be at least 20 minutes to ensure safe use.
50 mL† 165 mL/hr 20 minutes
100 mL 310 mL/hr 20 minutes
150 mL 310 mL/hr 30 minutes
250 mL 310 mL/hr 49 minutes

Preparation for Subcutaneous Injection

Remove the casirivimab and imdevimab vial(s) from refrigerated storage and allow to equilibrate to room temperature for approximately 20 minutes before preparation. Do not expose to direct heat. Do not shake the vials.

Inspect casirivimab and imdevimab vial(s) visually for particulate matter and discoloration prior to administration. Should either be observed, the vial must be discarded and replaced with a new vial. The solution for each vial should be clear to slightly opalescent, colorless to pale yellow.

  1. Casirivimab and imdevimab should be prepared using the appropriate number of syringes (see Table 5 and Table 6). Obtain 3 mL or 5 mL polypropylene Luer Lock syringes with luer connection and 21-gauge 1½ inch transfer needles.
  2. Withdraw the appropriate amount of solution into each syringe (see Table 5 and Table 6). Prepare all syringes at the same time.
  3. Replace the 21-gauge transfer needle with a 25-gauge or 27-gauge needle for subcutaneous injection.
  4. This product is preservative-free and therefore, the prepared syringes should be administered immediately. If immediate administration is not possible, store the prepared casirivimab and imdevimab syringes in the refrigerator between 2ºC to 8ºC (36ºF to 46ºF) for no more than 24 hours, or at room temperature up to 25ºC (77ºF) for no more than 8 hours. If refrigerated, allow the syringes to equilibrate to room temperature for approximately 20 minutes prior to administration.
Table 5: Preparation of 600 mg of Casirivimab and 600 mg of Imdevimab for Subcutaneous Injections
Prepare 600 mg of Casirivimab and 600 mg of Imdevimab Preparation of 4 Syringes
Using Casirivimab and Imdevimab Co-formulated Vial Withdraw 2.5 mL solution per syringe into FOUR separate syringes.
Using Casirivimab and Imdevimab Individual Vials
  • Casirivimab: Withdraw 2.5 mL solution per syringe into TWO separate syringes.
  • Imdevimab: Withdraw 2.5 mL solution per syringe into TWO separate syringes.
For total of 4 syringes.
Table 6: Preparation of 300 mg of Casirivimab and 300 mg of Imdevimab for Subcutaneous Injections for Repeat Dosing*
Prepare 300 mg of Casirivimab and 300 mg of Imdevimab Preparation of 2 Syringes
*
Subsequent repeat dosing every 4 weeks after initial 600 mg casirivimab and 600 mg imdevimab dosing for the duration of ongoing exposure.
Using Casirivimab and Imdevimab Co-formulated Vial Withdraw 2.5 mL solution per syringe into TWO separate syringes.
Using Casirivimab and Imdevimab Individual Vials
  • Casirivimab: Withdraw 2.5 mL solution into ONE syringe.
  • Imdevimab: Withdraw 2.5 mL solution into ONE syringe.
For total of 2 syringes.

Administration for Subcutaneous Injection

  • For the administration of 600 mg of casirivimab and 600 mg of imdevimab, gather 4 syringes (see Table 5) and prepare for subcutaneous injections.
  • For the administration of 300 mg of casirivimab and 300 mg of imdevimab, gather 2 syringes (see Table 6) and prepare for subcutaneous injections.
  • Administer the subcutaneous injections consecutively, each at a different injection site, into the thigh, back of the upper arm, or abdomen, except for 2 inches (5 cm) around the navel. The waistline should be avoided.
  • When administering the subcutaneous injections, it is recommended that providers use different quadrants of the abdomen or upper thighs or back of the upper arms to space apart each 2.5 mL subcutaneous injection of casirivimab and imdevimab. DO NOT inject into skin that is tender, damaged, bruised, or scarred.
  • Clinically monitor patients after injections and observe patients for at least 1 hour.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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