Regen-Cov

Generic name: casirivimab and imdevimab [ KAS-i-RIV-i-mab-and-im-DEV-i-mab ]
Drug class: Antiviral combinations

Medically reviewed by Philip Thornton, DipPharm. Last updated on Aug 23, 2023.

What is Regen-Cov?

Regen-Cov injection contains a combination of casirivimab and imdevimab, either supplied mixed in one vial or in two separate injection vials.

Regen-Cov is an investigational medicine being studied for use in treating conditions caused by coronavirus. It is not yet known if Regen-Cov is safe and effective.

Due to the high frequency of the Omicron BA.2 sub-variant, this drug is not currently authorized in any US region; therefore, this drug may not be administered for treatment of COVID-19 under the emergency use authorization (EUA) until further notice by the US FDA.

Regen-Cov is also for use in people who have been exposed to COVID-19 and:

• are not fully vaccinated against COVID-19; or

• are vaccinated but may not have built up enough immunity (because they have certain diseases or use certain medicines), and have been or may be exposed to people who are infected with COVID-19.

Regen-Cov is for use in adults and children at least 12 years old who weigh at least 88 pounds (40 kilograms).

The risk of COVID-19 symptoms becoming severe may be higher in people who:

• are overweight;

• have chronic kidney disease;

• have diabetes;

• have a weak immune system (caused by disease or by using certain medicine);

• have sickle cell disease;

• have a heart problem or high blood pressure;

• have a neurodevelopmental disorder such as cerebral palsy;

• have asthma or other chronic breathing disorder; or

• have a tracheostomy, gastrostomy, or positive pressure ventilation (not related to COVID-19).

There also may be a higher risk of severe COVID-19 symptoms in pregnant women and in adults who are 65 and older.

Casirivimab and imdevimab are mixed together into a single solution called Regen-Cov.

Regen-Cov has not been approved to treat coronavirus or COVID-19. However, these medicines may help prevent the need for emergency medical care or admission to a hospital because of COVID-19. Regen-Cov is not authorized for use in people who are already in the hospital or receiving supplemental oxygen for COVID-19.

Warnings

Due to the high frequency of the Omicron BA.2 sub-variant, this drug is not currently authorized in any US region; therefore, this drug may not be administered for treatment of COVID-19 under the EUA until further notice by the US FDA.

Before taking this medicine

To make sure Regen-Cov is safe for you, tell your doctor if you have:

• a COVID-19 vaccine;

• a severe allergic reaction to a COVID-19 vaccine;

• any serious or chronic illness;

• any allergies; or

• if you are pregnant or breastfeeding.

COVID-19 is more likely to cause serious illness or death in a pregnant woman. Not all risks are known yet, but being treated with Regen-Cov is likely to be less harmful than being infected with COVID-19 during pregnancy.

How is Regen-Cov given?

Regen-Cov is injected under the skin or into a vein by a healthcare provider.

When injected into a vein, Regen-Cov is given slowly over 20 to 50 minutes or longer. When injected under the skin, Regen-Cov is given as 2 to 4 separate injections into different areas of your body.

You will be watched for a short time after injection, to make sure you do not have an allergic reaction.

Regen-Cov is usually given as only one dose as soon as possible after you are exposed to or test positive for COVID-19, or within 10 days after the start of symptoms. You may need additional monthly doses if you continue to be exposed to COVID-19.

Being treated with Regen-Cov will not make you less contagious to other people. Keep using infection control methods such as self-isolation, social distancing, hand-washing, using protective face covering, disinfecting surfaces you touch a lot, and not sharing personal items with others.

Regen-Cov also may not keep you from becoming infected with coronavirus again. Being treated with this drug combination could also affect your body's immune response to a coronavirus vaccine. Regen-Cov is still being studied and all of their risks are not yet known.

Dosing information

Usual Adult Dose for COVID-19:

For investigational use only

At least 40 kg:
-IV infusion: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
-Subcutaneous injection: Casirivimab 600 mg and imdevimab 600 mg subcutaneously

Usual Adult Dose for Postexposure Prophylaxis:

For investigational use only

At Least 40 kg:
Single Dose:
-IV infusion: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
-Subcutaneous injection: Casirivimab 600 mg and imdevimab 600 mg subcutaneously

Repeat Dosing:
-IV infusion:
---Initial dose: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
---Subsequent doses: Casirivimab 300 mg and imdevimab 300 mg administered together as a single IV infusion every 4 weeks for the duration of ongoing exposure
-Subcutaneous injection:
---Initial dose: Casirivimab 600 mg and imdevimab 600 mg subcutaneously
---Subsequent doses: Casirivimab 300 mg and imdevimab 300 mg subcutaneously every 4 weeks for the duration of ongoing exposure.

Usual Pediatric Dose for COVID-19:

For investigational use only

12 years or older, weighing at least 40 kg:
-IV infusion: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
-Subcutaneous injection: Casirivimab 600 mg and imdevimab 600 mg subcutaneously.

Usual Pediatric Dose for Postexposure Prophylaxis:

For investigational use only

12 Years or Older, Weighing At Least 40 kg:
Single Dose:
-IV infusion: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
-Subcutaneous injection: Casirivimab 600 mg and imdevimab 600 mg subcutaneously

Repeat Dosing:
-IV infusion:
---Initial dose: Casirivimab 600 mg and imdevimab 600 mg administered together as a single IV infusion
---Subsequent doses: Casirivimab 300 mg and imdevimab 300 mg administered together as a single IV infusion every 4 weeks for the duration of ongoing exposure
-Subcutaneous injection:
---Initial dose: Casirivimab 600 mg and imdevimab 600 mg subcutaneously
---Subsequent doses: Casirivimab 300 mg and imdevimab 300 mg subcutaneously every 4 weeks for the duration of ongoing exposure

Comments:
-The US FDA issued an EUA to allow the emergency use of the unapproved product, casirivimab and imdevimab (co-formulated product and supplied as individual vials to be administered together), for postexposure 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 AND have been exposed to someone infected with SARS-CoV-2 consistent with close contact criteria per US CDC OR who are at high risk of exposure to someone infected with SARS-CoV-2 due to occurrence of SARS-CoV-2 infection in others in the same institutional setting; this product is not approved by the US FDA for this use.
---January 24, 2022: Due to the high frequency of the Omicron variant, this product is not currently authorized in any US region; therefore, this product may not be administered for postexposure prevention of COVID-19 under the EUA until further notice by the US FDA.
-Limitations of Authorized Use:
---This product is not authorized for postexposure prophylaxis of COVID-19 in geographic regions where exposure is likely to have been to a nonsusceptible SARS-CoV-2 variant, based on available information including variant susceptibility to this product and regional variant frequency.
---Postexposure prophylaxis with this product is not a substitute for vaccination against COVID-19.
---This product is not authorized for preexposure prophylaxis for prevention of COVID-19.
-Either IV infusion or subcutaneous injection can be used.
-Casirivimab and imdevimab should be administered together as soon as possible after exposure to SARS-CoV-2.
-Repeat dosing may be appropriate for individuals with 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.
-No dose adjustment recommended in pregnant or lactating patients.
-The optimal dosing regimen has not been established for treatment of COVID-19; the recommended dosing regimen may be updated as clinical trial data become available.
-Individuals are considered fully vaccinated 2 weeks after their second vaccine dose in a 2-dose series, or 2 weeks after a single-dose vaccine. For additional information: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html#vaccinated
-For additional information regarding individuals with immunocompromising conditions: https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html
-Close contact with an infected individual is defined as: being within 6 feet for at least 15 minutes (total), providing care at home to someone who is sick, having direct physical contact with the person (e.g., hugging, kissing), sharing eating/drinking utensils, or being exposed to respiratory droplets from an infected person (e.g., sneezing, coughing). For additional information: https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/quarantine.html
-For additional information: https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#coviddrugs

Use: For the postexposure 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 (e.g., individuals with immunocompromising conditions including those taking immunosuppressive agents) AND
---have been exposed to someone infected with SARS-CoV-2 consistent with close contact criteria per US CDC OR
---who are at high risk of exposure to someone infected with SARS-CoV-2 due to occurrence of SARS-CoV-2 infection in others in the same institutional setting.

What happens if I miss a dose?

Call your doctor for instructions if you are on a monthly dose schedule and you miss an appointment for your injection.

What happens if I overdose?

In a medical setting an overdose would be treated quickly.

What should I avoid while receiving Regen-Cov?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Regen-Cov side effects

Get emergency medical help if you have signs of an allergic reaction to Regen-Cov: hives, itching; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the Regen-Cov injection. Tell your caregiver right away if you have:

• throat irritation, swelling in your face or throat;

• dizziness, a light-headed feeling (like you might pass out);

• chest pain, wheezing, shortness of breath;

• fever, chills, sweating, nausea, flushing (sudden warmth, redness, or tingly feeling);

• fast or slow heartbeats, headache, pounding in your neck or ears;

• weakness, tiredness;

• rash, itching; or

• muscle pain.

Call your doctor if you have new or worsening symptoms after the infusion, such as fever, confusion, weakness, tiredness, trouble breathing, or fast or slow heartbeats.

Less serious side effects may also occur, or you may have none at all. Not all possible side effects are known.

This is not a complete list of Regen-Cov's side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Regen-Cov?

Other drugs may interact with casirivimab and imdevimab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Regen-Cov only for the indication prescribed.

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

Medical Disclaimer

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