Nucala vs. Dupixent: 6 Differences Between These Biologics for Asthma

If your asthma symptoms aren’t being managed with your current treatment regimen, your healthcare provider may consider prescribing you a biologic. Biologics are medications that come from living sources. And when it comes to asthma, they’re made to specifically target substances in the body that can cause or worsen asthma symptoms.

Nucala (mepolizumab) and Dupixent (dupilumab) are two injectable biologics that treat specific types of asthma. They’re also approved to treat certain health conditions that may be more common in people with asthma. 

Nucala and Dupixent have a few similarities. But there are also several key differences that set them apart. Below, we discuss six of these differences.

1. Dupixent is approved to treat broader groups of people with asthma

Nucala and Dupixent are both FDA approved as add-on treatments for eosinophilic asthma. Eosinophils are white blood cells that normally help fight off infections. But when levels are too high, they can also sometimes cause inflammation in certain areas of the body, such as in the lungs. This can contribute or lead to asthma symptoms.

For people age 6 and older, Nucala is approved to treat severe eosinophilic asthma. Dupixent can be given to people in this same age group for moderate-to-severe eosinophilic asthma. And in addition to eosinophilic asthma, Dupixent is also approved to treat asthma in people who need oral steroid treatment for asthma management.

2. Nucala and Dupixent work in a different way for asthma

Nucala and Dupixent are both monoclonal antibodies, which are lab-made antibodies made to target specific substances in the body. But they target different proteins that contribute to asthma symptoms.

Nucala works by blocking a protein called interleukin-5 (IL-5). IL-5 helps eosinophils grow and activate in the body. As mentioned above, too many eosinophils can be a problem when it comes to asthma symptoms. Blocking IL-5 helps decrease the amount of eosinophils in the body. This can lower inflammation and help you breathe easier.

Dupixent doesn’t lower the amount of eosinophils in the body like Nucala, but it targets two key sources of lung inflammation. It blocks the proteins interleukin-4 (IL-4) and interleukin-13 (IL-13), which are thought to be involved in allergic and eosinophilic inflammation in the airways. By blocking them, Dupixent reduces inflammation in the lungs, which can help improve lung function.

Keep in mind: Both Nucala and Dupixent are meant for long-term management of asthma. They won’t work during a sudden asthma attack.

Understanding and Treating Your Asthma: What to Ask Your Doctor

Written by Mandy Armitage, MD

3. Nucala is usually injected less frequently than Dupixent

Another difference between Nucala and Dupixent is how often they’re administered for asthma. For most people, Nucala is injected less frequently than Dupixent.

Regardless of your age, Nucala is injected under the skin once every 4 weeks (1 month). Dupixent has slightly more complicated dosage recommendations. For most people, it’s injected under the skin every 2 weeks. But children age 6 to 11 years old who weigh less than 30 kg (66 lbs) receive doses every 4 weeks.

Additionally, people age 12 and older starting treatment with Dupixent receive a loading dose. This means they’ll receive two back-to-back injections for the first dose. Children aged 6 to 11 years old don’t typically require a loading dose, unless they’re also receiving Dupixent for moderate-to-severe eczema.

4. Nucala and Dupixent can cause different side effects

Nucala and Dupixent are both administered as injections, which can result in injection site reactions. This can mean pain, swelling, and redness where a dose is injected. Other side effects are also possible with the medications, and these side effects may differ.

In clinical studies, people receiving Nucala reported side effects such as headache, back pain, and fatigue. But it’s important to note that people receiving a placebo (an injection without medication) also reported these side effects at a similar rate. People receiving Dupixent, on the other hand, reported side effects such as mouth and throat pain in clinical studies. 

It’s also possible for eosinophil levels to increase after starting treatment with Dupixent. But this appears to be temporary, with levels returning to baseline after several months. While rare, higher eosinophil levels may result in a rash or worsening asthma symptoms.

Both Nucala and Dupixent carry a warning about helminth (parasitic) infections. This is because eosinophils normally help the body fight off this type of infection. During clinical trials, there were a few cases of parasitic infections in children receiving Dupixent. While rare, parasitic infections have been reported with both medications after their approval.

Note: The side effects listed above aren’t all of the possible side effects of Nucala and Dupixent. Follow up with your healthcare provider to learn more.

5. Dupixent can be stored at room temperature longer than Nucala

After proper training from your healthcare team, you (or a caregiver) may have the option to administer Dupixent or Nucala at home. In this case, proper storage is key. 

If you’re on the go or travel frequently, Dupixent may offer you more flexibility. Both Nucala and Dupixent should be stored in a refrigerator (between 36 to 46 degrees Fahrenheit) until you’re ready for a dose.

If you don’t have access to a fridge, unopened Nucala cartons can be stored out of the refrigerator (up to 86 F) for up to 7 days. Once removed from its carton, Nucala must be used within 8 hours. When taken out of the refrigerator, Dupixent can be stored at room temperature (up to 77 F) for up to 14 days, but it should be kept in its original carton to protect it from light.

Keep in mind: If you’ve kept either medication outside of the refrigerator for longer than the time periods outlined above, throw it away. And don’t take either medication if it has been frozen.

6. Nucala and Dupixent have different approved uses beyond asthma

In addition to treating asthma, Nucala and Dupixent have several other approved uses. For example, they’re both approved for chronic rhinosinusitis with nasal polyps, which tends to be common in people with asthma.

What’s more, Nucala can be used to treat other health conditions associated with high eosinophil levels. These conditions include eosinophilic granulomatosis with polyangiitis and hypereosinophilic syndrome.

Dupixent has a growing list of approved uses. In addition to asthma, it’s currently approved to treat moderate-to-severe atopic dermatitis (eczema) and prurigo nodularis, a condition that causes itchy bumps on the skin. Dupixent was also the first medication approved for eosinophilic esophagitis, with approval pending for children as young as 1 year old. It could also be approved for chronic pulmonary obstructive disease (COPD) in 2024.

Your healthcare provider may consider any other health conditions you have when recommending the best treatment option for you. This may be Nucala, Dupixent, or a different medication.

Ways to save on Nucala and Dupixent

You may receive Nucala or Dupixent in the mail from a specialty pharmacy if you administer your medication at home. Your care team will typically work with your insurance company to confirm coverage. Your team will also find out if you’re eligible for a copay savings card or patient assistance program.

The copay savings cards offered by the manufacturers of Nucala and Dupixent can make the medications more affordable for qualifying people. Other resources, such as patient assistance programs, are also available. If you’re eligible for any of these programs, you could pay as little as $0 per fill for Nucala or $0 per fill for Dupixent.

Why trust our experts?

Written by:

Kristianne Hannemann, PharmD

Kristianne Hannemann, PharmD, is a licensed pharmacist in California. She has been a retail pharmacy manager and staff pharmacist for over 7 years and has contributed drug information content to different health companies.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Our editorial standards

Meet our experts