Severe asthma affects roughly 2 million people in the United States. It is hard to control — even with inhaled steroid medicines and additional therapies. More than 80% of cases are linked to type 2 inflammation. This type of inflammation is driven largely by eosinophils, which are white blood cells that trigger airway swelling (inflammation) and make asthma harder to manage. When eosinophil levels in the blood are very high, the condition is referred to as severe eosinophilic asthma.
Exdensur (depemokimab) is a new type of ultra-long-acting medicine that is used as an add-on asthma treatment for certain people with severe eosinophilic asthma to reduce the risk of asthma attacks.
How Does Exdensur Work for Severe Asthma?
Exdensur is a lab‑made antibody that targets a protein in the body called interleukin‑5 (IL‑5). IL‑5 plays a key role in telling the body to make and activate eosinophils. By blocking IL-5, Exdensur lowers the number of eosinophils in your body. This helps reduce inflammation in your airways. Less inflammation means your airways are less irritated and less likely to flare up, which can help lower your risk of asthma attacks.
While Exdensur helps prevent severe asthma attacks, it does not treat sudden breathing problems associated with asthma, so you will still need your rescue inhaler.
How Do I Use Exdensur?
Exdensur is given as an injection under the skin just twice a year by a health care provider. Exdensur’s unique design allows it to remain in the body longer and provide long-term asthma control. Exdensur is meant to be used as an add-on therapy along with your regular asthma treatments, not instead of them.
How Was It Studied for Severe Eosinophilic Asthma?
Exdensur was studied in two clinical trials called SWIFT 1 and SWIFT 2. These studies included people aged 12 years or older with severe eosinophilic asthma. To take part in the studies, participants had to have had at least two asthma attacks in the previous year that required treatment with steroid medicines taken by mouth. They also had to be taking medium- or high-dose inhaled steroid medicines for at least one year, along with at least one additional controller medicine for at least three months.
A total of 792 people took part in the two studies combined. Participants were randomly assigned to receive either Exdensur 100 mg or a placebo (containing no active medicine) given as an injection under the skin twice a year. A dose was given at the beginning of the study and again 26 weeks later. Neither the participants nor the researchers knew who was receiving Exdensur and who was receiving a placebo. All participants continued taking their regular asthma medications, such as inhaled steroid medicines and long-acting bronchodilators.
At the start of the studies, the average age of participants was about 53 years, and most were between the ages of 18 and 64 years. Most participants (71%-83%) were White, and 17%-29% identified as “Other” races, including Black, Asian, and mixed race, along with ethnic groups of American Indian, Alaska Native, Native Hawaiian, or other Pacific Islander. On average, participants had been living with asthma for 20 to 25 years. About 90% of participants had high blood eosinophil levels of at least 150 cells per microliter, and 46% to 60% had levels of at least 300 cells per microliter.
The main goal of the studies was to determine whether Exdensur could reduce the number of asthma attacks over 12 months compared with a placebo.
What Did the Studies Show?
Both the SWIFT-1 and SWIFT-2 studies showed that people with severe eosinophilic asthma who received Exdensur plus their standard treatment experienced fewer asthma attacks over one year compared to those who received a placebo plus their standard treatment.
SWIFT-1:
- People in the Exdensur group had an average of 0.46 asthma attacks in one year, while those in the placebo group had an average of 1.11 asthma attacks.
- People who received Exdensur had 58% fewer asthma attacks compared with those receiving a placebo.
SWIFT-2:
- People using Exdensur had 0.56 asthma attacks in one year, while those on placebo had 1.08 attacks on average.
- People who received Exdensur had 48% fewer asthma attacks compared with those in the placebo group.
When researchers combined results from both studies, Exdensur reduced asthma attacks by 54% compared with placebo.
Also, fewer people who received Exdensur needed hospitalization (1%) or emergency care (4%), compared with those receiving a placebo (8%-10%). The studies also showed a 72% reduction in severe asthma attacks that required a hospital stay or an emergency room visit among patients treated with Exdensur.
Your results may differ from what was seen in clinical studies.
How Can I Prevent and Manage Exdensur Side Effects?
People who use Exdensur may be more likely to have an infection that causes a runny nose and sore throat. The best way to prevent infection is to reduce your exposure to germs by washing your hands and avoiding people who are sick. You should also stay current on vaccines, such as the annual flu vaccine.
Exdensur may reduce your body’s ability to fight certain infections, including parasitic helminth (worm) infections. If you have a worm infection, talk to your health care provider about treating the infection before starting Exdensur.
Tell your health care provider if you have had allergic reactions to any asthma medicines in the past. Contact your health care provider right away if you experience any signs and symptoms of an allergic reaction, including breathing problems; swelling of the face, lips, mouth, tongue, or throat; dizziness or lightheadedness; or itching, hives, or skin rash.
Contact your health care provider right away if your breathing problems get worse or if you need to use your rescue inhaler more often than before.
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. If you experience anything that you think may be caused by Exdensur, you can also report side effects to the FDA at 800-FDA-1088 (800-332-1088).
What Kinds of Drug Interactions May Happen With Exdensur?
If you use other medicines for your asthma, talk with your health care provider about when and how to use each of them. Do not stop or change any medicines you use for asthma without first talking to your health care provider.
Tell your health care provider if you use a medicine called a corticosteroid (steroid), such as an inhaled corticosteroid and/or one that you take by mouth. Your health care provider will tell you if you need to make any changes to your corticosteroid dose. Do not make any changes on your own, including stopping a corticosteroid. If a corticosteroid dose is lowered, you may have withdrawal symptoms or symptoms from a condition that had been hidden by the corticosteroid. Any reductions in a corticosteroid dose need to be supervised by your health care provider.
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if Exdensur is right for you.
Is There Any Cost Assistance Available?
Yes. There is a cost savings and support program offered by the drugmaker that may allow you to pay as little as $0 for your Exdensur prescription. Your eligibility depends on whether you have prescription insurance and the type of insurance you have. You can find out more information at www.togetherwithgsk.com/exdensur/patient/cost-support/ or by calling 844-225-5894.
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