Nucala (mepolizumab)

Medically Reviewed By Elizabeth Scheffel, PharmD

About Nucala

Nucala is a brand-name prescription medication. It’s approved by the Food and Drug Administration (FDA) to treat the following conditions:

For details about these conditions and how the drug treats them, see the “Nucala: Uses” section below.

Note: To treat severe eosinophilic asthma, Nucala is a treatment you’ll take regularly whether you have symptoms or not. Nucala should not be used as a rescue inhaler to treat an asthma attack or sudden worsening of asthma symptoms. While using Nucala, continue using your rescue inhaler as needed according to your doctor’s instructions. If you ever have asthma symptoms that feel life threatening, call 911 or seek emergency medical help right away.

Key points

The following table provides key facts about Nucala.

Active drug mepolizumab, which is a biologic
Drug class interleukin-5 (IL-5) antagonist
Forms available in the following, which are given by subcutaneous injection:  
• liquid in a single-dose prefilled syringe
• liquid in a single-dose prefilled auto-injector
• powder that’s made into a liquid

Finding a healthcare professional

If you’re interested in taking this drug, search here to find a doctor who might prescribe it.

Nucala: Generic or biosimilar

Nucala contains the active drug mepolizumab, which is a type of drug called a biologic. It only comes as a brand-name medication. It’s not available as a biosimilar medication.

Biosimilars refer to drugs that are similar to a brand-name biologic drug (the parent drug). It’s not possible to make an exact copy of biologic drugs because they’re made from living cells. On the other hand, generics refer to drugs made from chemicals. Generics are exact copies of the active drug found in a brand-name medication.

Biosimilars are considered to be just as effective and safe as their parent drug. And similar to generics, biosimilars tend to cost less than brand-name medications.

Nucala: Side effects

As with most drugs, it’s possible to have side effects with Nucala. These can include some mild side effects but also some serious ones.

To learn more about Nucala’s side effects, talk with your doctor or pharmacist. They may also provide information about managing certain side effects of this drug.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Nucala, you can do so through MedWatch.

Mild and serious side effects

Mild and serious side effects of Nucala are listed below. This article does not include all of Nucala’s possible side effects.

Mild side effects

Mild side effects* of Nucala may include:

In addition to the side effects above, people who used Nucala to treat chronic rhinosinusitis with nasal polyps (CRSwNP) have also reported:

  • mouth pain
  • joint pain
  • diarrhea
  • fever
  • nasal dryness
  • skin rash

Most times, mild side effects of a drug go away within a few days or a couple of weeks. Talk with your doctor or pharmacist if any side effects become severe or don’t go away.

* This is not a complete list of Nucala’s mild side effects. To learn about other mild side effects of this drug, ask your doctor or pharmacist. Or you can view the drug’s prescribing information.
† To learn more about allergic reaction, see below.

Serious side effects

Serious side effects of Nucala may include:

Serious side effects from Nucala aren’t common, but they are possible. If you have serious side effects, call your doctor right away. However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

* To learn more about allergic reaction, see below.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Nucala. A more severe allergic reaction is rare but possible.

Allergic reactions weren’t common in Nucala’s clinical studies.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction symptoms
flushing • swelling under your skin, possibly in your hands, feet, lips, or eyelids
rash • swelling in your throat or mouth
• itching trouble breathing

If you have an allergic reaction to Nucala, call your doctor right away. This is important because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Nucala: Cost

As with other medications, prices for Nucala may vary. The drug’s price will depend on factors such as:

Cost considerations for Nucala

Here’s a list of things to consider when looking into the cost of Nucala.

Option for a 90-day supply. For some drugs, it’s possible to get a 90-day supply. If this option is approved by your insurance company, it can help lower the cost of the drug. It can also help you avoid frequent trips to your pharmacy. If you’d like to learn more about this option, ask your doctor, pharmacist, or insurance company.

Need for prior authorization. Before insurance coverage for Nucala is approved, your insurance company may require prior authorization. In this case, your doctor and insurance company will communicate about your prescription for Nucala. Then, the insurance company will decide if the drug will be covered. To find out if you need prior authorization for Nucala, contact your insurance company.

Possible cost assistance options. Financial assistance to help lower the cost of Nucala is available. The Nucala Co-pay Program may help reduce the drug’s cost. To learn more and see if you’re eligible for support, visit the manufacturer’s website.

View this page to learn about insurance coverage for Nucala. Also, check out this article to learn about ways to save on prescription drugs.

Use of a specialty pharmacy. Nucala is only dispensed from specialty pharmacies. These pharmacies are authorized to handle certain drugs considered specialty medications. These medications may be expensive or require help from healthcare professionals to be used safely and effectively. Ask your doctor which specialty pharmacy they’ll prescribe Nucala through.

Use of a mail-order pharmacy. Nucala may be dispensed through mail-order pharmacies. Getting your prescription through a mail-order pharmacy could lower its cost. It can also allow you to get the drug without leaving home. To find out more about this option, check with your doctor, pharmacist, or insurance company.

Availability of a biosimilar form. Nucalaonly comes as a brand-name medication. It’s not available as a biosimilar medication.

Biosimilars refer to drugs that are similar to a brand-name biologic drug (the parent drug). It’s not possible to make an exact copy of biologic drugs because they’re made from living cells. Biosimilars are considered to be just as effective and safe as their parent drug. Also, they tend to cost less than brand-name medications.

Nucala: Uses

Prescription drugs, such as Nucala, are approved by the Food and Drug Administration (FDA) to treat certain conditions.

Using Nucala for eosinophilic asthma

Nucala may be used to treat severe eosinophilic asthma in adults and children ages 6 years and older.

Eosinophilic asthma is a form of asthma caused by high levels of eosinophils. Eosinophils are a type of white blood cell.

During an asthma attack, eosinophils release chemicals that cause your airways to narrow and tighten. This makes it difficult to breathe. People with eosinophilic asthma have eosinophils that release these chemicals abnormally.

Symptoms of eosinophilic asthma include:

If you have asthma and you’re using Nucala, you should continue using your rescue inhaler as directed by your doctor. Nucala should not be used as a rescue inhaler to treat an asthma attack or sudden worsening of asthma symptoms. If you ever have asthma symptoms that feel life threatening, call 911 or seek emergency medical help right away.

You should also continue taking other asthma medications as directed by your doctor. Nucala is meant to be used as an add-on therapy. That means it’s used along with other asthma medications you may take.

Using Nucala for chronic rhinosinusitis

Nucala may be used to treat chronic rhinosinusitis with nasal polyps (CRSwNP) in adults.

With chronic rhinosinusitis, your sinuses are irritated for 12 weeks or longer. Nasal polyps are growths found inside of your nose or the lining of your sinuses. Nasal polyps aren’t painful, but they can make it difficult to breathe.

Symptoms of CRSwNP include:

  • trouble breathing through your nose
  • pressure or pain in your face, particularly in your cheeks, forehead, or nose
  • sore throat
  • aches in your jaw or upper teeth
  • postnasal drip

You should continue taking other CRSwNP medications as directed by your doctor. Nucala is meant to be used as an add-on therapy. That means it’s used along with other CRSwNP medications you may take.

Using Nucala for eosinophilic granulomatosis with polyangiitis

Nucala may be used to treat eosinophilic granulomatosis with polyangiitis (EGPA) in adults.

EGPA is a very rare condition. It was formerly known as Churg-Strauss syndrome. EGPA is a form of vasculitis (inflammation in your blood vessels). This inflammation can prevent body organs from getting enough blood, causing damage to them and body tissues.

With EGPA, this inflammation affects small blood vessels. Typically, this affects the lungs, but it may affect any part of your body.

Symptoms of EGPA include:

  • nasal polyps
  • adult-onset asthma
  • high level of eosinophils (a type of white blood cell)
  • fever
  • fatigue
  • sudden weight loss
  • pain in your muscles or joints
  • sudden loss of strength in your hands or feet

Using Nucala for hypereosinophilic syndrome

Nucala may be used to treat hypereosinophilic syndrome (HES) in adults and children ages 12 years and older. Specifically, it’s used to treat HES that is present for at least 6 months.

HES is a group of rare conditions rather than just one condition. All of these conditions involve high levels of eosinophils (a type of white blood cell). In addition, all of them show evidence that at least one body organ, such as your lungs or heart, is affected. (Over time, high eosinophil levels can lead to organ damage.)

Symptoms of HES can vary depending on which organ it affects. For example, if it affects your lungs, you may cough, have difficulty breathing, and have frequent upper respiratory infections. However, regardless of the organ or organs involved, the most common symptom of HES is skin rash.

Using Nucala with other drugs

Nucala is a treatment you take regularly, whether you’re experiencing symptoms or not.

If you have asthma and you’re using Nucala, you should continue using your rescue inhaler as directed by your doctor. Nucala should not be used as a rescue inhaler to treat an asthma attack or sudden worsening of asthma symptoms. If you ever have asthma symptoms that feel life threatening, call 911 or seek emergency medical help right away.

In addition, you should also continue taking other asthma medications as directed by your doctor. Nucala is meant to be used as an add-on therapy to treat severe eosinophilic asthma. That means it’s used along with other asthma medications you may take.

Nucala is also used as an add-on therapy to treat CRSwNP. This means you’ll use it with other medications to treat your condition.

Using Nucala in children

Nucala is approved for some uses in children. These include the following:

  • to treat severe eosinophilic asthma in children ages 6 years and older
  • to treat HES in children ages 12 years and older

To learn about these conditions, see the information directly above.

Finding a healthcare professional for Nucala

Check out these resources for finding a healthcare professional who may prescribe Nucala for you:

Nucala: Dosage

Below are dosages that are commonly recommended for Nucala. However, you should take the dosage your doctor prescribes for you. They’ll recommend the dosage that’s best for your needs.

The dosage of Nucala that your doctor prescribes will depend on factors such as:

  • your age
  • the condition you’re using Nucala to treat and the severity of the condition

Nucala’s forms and strengths

Nucala is available as follows.

Form Strength
liquid in a single-dose prefilled syringe • 40 milligrams per 0.4 milliliter (mg/mL)
• 100 mg/mL
liquid in a single-dose prefilled auto-injector • 100 mg/mL
powder to be made into a liquid for subcutaneous injection*   • 100 mg (100 mg/mL once mixed by a healthcare professional)

* This form is given only by a healthcare professional.

Nucala’s recommended dosages

Recommended dosages for Nucala in adults and children are described below.

Adult dosage

The recommended dosages for Nucala in adults are as follows.

Use Dose Frequency
severe eosinophilic asthma 100 milligrams (mg) every 4 weeks
chronic rhinosinusitis with nasal polyps (CRSwNP) 100 mg every 4 weeks
eosinophilic granulomatosis with polyangiitis (EGPA) 300 mg, given as three separate 100-mg injections on the same day every 4 weeks
hypereosinophilic syndrome (HES) 300 mg, given as three separate 100-mg injections on the same day every 4 weeks

Child dosage

The recommended dosages for Nucala in children are as follows.

Use Dose Frequency
severe eosinophilic asthma in children ages 6 to 11 years 40 mg every 4 weeks
severe eosinophilic asthma in children ages 12 years and older 100 mg every 4 weeks
hypereosinophilic syndrome (HES) in children ages 12 years and older 300 mg, given as three separate 100-mg injections on the same day every 4 weeks

Dosage considerations

Below are some things to consider about Nucala’s dosage.

  • Missing a dose. Dose frequency is typically every 4 weeks. If you miss a dose of Nucala, take it as soon as you remember. However, if it’s been 4 weeks or longer and it’s time for your next dose, skip the missed dose and take the next dose right away. Don’t take more than one dose of Nucala at a time. Try these medication reminder options to help avoid missing doses. You could also set an alarm, use a timer, or download a reminder app on your phone.
  • Length of treatment. Doctors typically prescribe Nucala as a long-term treatment. You’ll likely take it long term if you and your doctor feel it’s safe and effective for your condition.

Nucala: Alternatives

Doctors may prescribe drugs other than Nucala for your condition. Certain drugs may work better for you than others.

In addition to other uses, Nucala is prescribed to treat severe eosinophilic asthma in certain people. Here’s a summary of other drugs that doctors sometimes prescribe for asthma.

To learn more about some alternatives of Nucala, view the following articles:

Your doctor can tell you about other similar drugs, such as dupilumab (Dupixent).

For additional information about alternatives to Nucala, ask your doctor. They can tell you about other medications that could be prescribed for your condition.

Nucala: How it works

Nucala is approved to treat the following conditions:

To learn more about these conditions, see the “Nucala: Uses” section above.

A drug’s mechanism of action refers to how it works. Nucala’s mechanism of action is to block the actions of a protein called interleukin-5 (IL-5). Interleukins are proteins that play an important role in your immune system. They send signals that cause inflammation.

Inflammation can help your body in certain situations, such as when fighting infection or healing a wound. However, with certain medical conditions, IL-5 inappropriately sends signals and causes inflammation. For example, with eosinophilic asthma, IL-5 signals your immune system to make and release eosinophils in excess.

By blocking the actions of IL-5, Nucala helps reduce inflammation. This helps treat symptoms of certain inflammatory conditions, such as eosinophilic asthma.

How long does Nucala take to start working?

Nucala doesn’t work right away. The drug works gradually to treat symptoms of your condition over time. It may take several weeks before you begin noticing reduced symptoms.

Your doctor can tell you more about how they’ll monitor whether or not Nucala is working for you.

Nucala: Questions you may have

Here are some common questions about Nucala and brief answers to them. If you’d like to know more about these topics, ask your doctor.

Does Nucala cause hair loss?

No, Nucala isn’t known to cause hair loss. This wasn’t a side effect reported in the drug’s clinical studies.

Some other medications used to treat the same conditions as Nucala may cause hair loss. For example, doctors may prescribe methotrexate to treat eosinophilic granulomatosis with polyangiitis (EGPA). Hair loss is a known side effect of methotrexate.

Talk with your doctor if you’re concerned about hair loss during treatment for your condition.

Will I have weight gain with Nucala?

No, Nucala isn’t known to cause weight gain. This wasn’t a side effect reported in the drug’s clinical studies.

Doctors commonly prescribe medications in the corticosteroid drug class to treat the same conditions as Nucala. These conditions include eosinophilic granulomatosis with polyangiitis (EGPA) and eosinophilic asthma. Weight gain is a known side effect of corticosteroids, such as prednisone.

Talk with your doctor if you’re concerned about weight gain during treatment for your condition.

Do doctors prescribe Nucala for COPD?

Nucala isn’t approved for treating chronic obstructive pulmonary disease (COPD). COPD refers to a group of inflammatory lung conditions that last long term.

Some clinical studies have suggested that people had benefit in using Nucala for this condition. However, some questions were raised about how the studies were conducted. Because of these concerns, in 2018 the Food and Drug Administration (FDA) did not approve Nucala for treating COPD.

Many drugs have approval by the FDA to treat COPD. If you’d like to learn more about treatments for this condition, talk with your doctor or pharmacist.

Nucala: Consuming alcohol during treatment

Alcohol and Nucala don’t have any known interactions.

However, alcohol and Nucala can cause some of the same side effects, including headache, fatigue, and abdominal pain. So, combining the two may raise your risk of these side effects.

Ask your doctor whether there’s a safe amount of alcohol to be consumed during treatment with Nucala.

Nucala: Interactions

Nucala isn’t known to interact with other medications, supplements, or foods. However, this doesn’t mean interactions can’t occur with Nucala.

Different interactions can cause different effects. Some interactions can interfere with a drug’s effectiveness. Others can increase a drug’s side effects or cause them to be severe.

Before you start Nucala, be sure to tell your doctor about any medications, herbs, vitamins, or supplements you take. They can check for any possible interactions between these products and Nucala, including new interactions that may be discovered during your treatment.

For information about drug-condition interactions, see the “Nucala: Precautions” section below.

Nucala: How it is given

Your doctor will recommend how you’ll give Nucala. It’s important that the drug is administered exactly as your doctor instructs.

Nucala is given by subcutaneous injection. Your doctor or a healthcare professional will show you how to give these injections at home. They may also show a family member or caregiver how to give the injections if you’re unable or uncomfortable giving them yourself. You may also choose to continue having a healthcare professional administer the doses.

Questions about giving Nucala

Here’s a list of common questions related to giving Nucala.

  • When should I give Nucala? A dose of Nucala should be given once every 4 weeks. Try these medication reminder options to help avoid missing doses of Nucala. You could also set an alarm, use a timer, or download a reminder app on your phone.
  • Do I need to give Nucala with food? Nucala injections can be given with or without food.
  • Is there a best time of day to give Nucala? No, there’s no best time of day to give Nucala. You may take a dose at a time that’s convenient for you or easy to remember.

Nucala: Using while pregnant

It’s not fully understood whether it’s safe to use Nucala while pregnant. Information about using the drug in pregnant people is limited.

In animal studies, Nucala didn’t cause harm to offspring born to animals receiving the drug. However, animal studies don’t always predict how a drug will affect people.

It is known that having asthma that isn’t treated can raise the risk of complications during pregnancy. (Keep in mind that Nucala is used to treat a certain type of asthma.) These complications include high blood pressure in pregnant people and low birth weight in newborns.

If you and your doctor agree that you’ll take Nucala while pregnant, consider joining the drug’s pregnancy registry. Pregnancy registries gather data about the safety of using drugs such as Nucala during pregnancy. They help doctors and patients make safe choices about the treatments they’ll use. To learn more or sign up, call 877-311-8972 or visit the registry website.

Nucala and birth control needs

Doctors aren’t sure whether it’s safe to take Nucala during pregnancy. Talk with your doctor about your birth control needs with Nucala if you’re sexually active and you or your partner can become pregnant. Your doctor can recommend if you should use birth control with this medication.

Nucala: Using while breastfeeding

It’s not known whether Nucala is safe to use while breastfeeding. Information isn’t available on whether or not the drug passes into human breast milk or causes side effects in a breastfed child.

Talk with your doctor about feeding options for your child if you’re using Nucala.

Nucala: Precautions

Tell your doctor about your health history before starting treatment with Nucala. Your doctor may not recommend this medication if you have certain factors affecting your health or specific medical conditions. These situations are considered drug-condition interactions.

These factors and conditions include those listed below.

  • Helminth (parasite) infection. Be sure to tell your doctor if you’ve recently had a helminth infection before you begin treatment with Nucala. (A helminth infection is a type of parasitic infection caused by worms.) Nucala may make it harder to treat parasitic infections. Your doctor will likely want to treat your infection before prescribing Nucala.
  • Allergic reaction. Your doctor will likely not prescribe Nucala if you’ve had an allergic reaction to it or any of its ingredients. To find out about other treatment options, talk with your doctor.
  • Pregnancy. If you’d like additional information about taking Nucala while pregnant, view the “Nucala: Using while pregnant” section above.
  • Breastfeeding. If you’d like additional information about taking Nucala while breastfeeding, view the “Nucala: Using while breastfeeding” section above.

To learn more about effects of Nucala that could be harmful, see the “Nucala: Side effects” section above.

Nucala: Questions for your doctor

If you have questions about Nucala, talk with your doctor. They can help advise you on whether Nucala could be a good treatment option for you.

Here’s a list of questions you may want to ask your doctor:

  • If Nucala isn’t working for me, is there a higher dose I can try?
  • I travel frequently. How should I travel with and store my Nucala syringes?
  • If my insurance doesn’t cover Nucala, what are my treatment options?

Your doctor may also tell you about other treatment options for your condition. You may find this article helpful in learning about alternative drugs for asthma. And view our selection of videos on asthma.

Disclaimer: Healthgrades has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Medical Reviewer: Elizabeth Scheffel, PharmD
Last Review Date: 2022 Jul 17
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.