Severe asthma occurs when affected people need medium- to high-dose inhaled steroid medicines (corticosteroids) plus an additional therapy or their condition remains uncontrolled despite treatment. More than 80% of severe asthma cases are driven by type 2 inflammation, which is associated with elevated eosinophil levels. Severe asthma affects about 2 million people in the U.S., and about half still experience frequent flare-ups that can lead to hospitalizations, emergency care, and higher health care costs.
Exdensur is a lab-made antibody that blocks a protein called interleukin-5 (IL-5), which promotes growth, activation, and survival of eosinophils. By inhibiting IL-5, this medicine reduces eosinophil production and helps lower the inflammation that can lead to asthma attacks.
Exdensur’s unique protein design allows it to remain in the body longer and provide sustained relief. Unlike other asthma medications that require frequent doses, Exdensur is given as two under-the-skin injections a year. Despite the benefits of biologics, only 20% of eligible U.S. patients receive them, leaving many at risk of worsening disease. This ultra-long-acting option may help expand biologic use, particularly for patients who struggle with more frequent dosing.
Why Was It Approved?
The FDA approval of Exdensur was based on clinical studies which showed that people with severe eosinophilic asthma who received Exdensur added to their standard treatment experienced fewer asthma attacks and flare-ups over a year than those who received placebo plus standard care.
The FDA approval is based on two phase 3 trials involving more than 760 people with severe eosinophilic asthma who continued their standard treatment and received either Exdensur (two injections per year) or a placebo. Over 52 weeks, Exdensur reduced asthma attacks by 58% in one study and 48% in the other, with patients taking this medicine experiencing fewer attacks per year than those on the placebo (yearly rate of significant asthma flare-ups, 0.46 vs 1.11 and 0.56 vs 1.08, respectively, in the two studies). Fewer patients on this medicine required hospitalization or emergency care (1% and 4%, respectively) compared with those on placebo (8%-10%, respectively), and a combined analysis showed a 72% reduction in severe attacks needing hospital or emergency room visits.
The treatment was well tolerated, with side effects similar to those seen for a placebo. The most common side effects of Exdensur include mild infections such as the common cold or sinus infections; allergy-like symptoms such as sneezing, stuffy or runny nose, and nasal itching; flu or flu-like symptoms; joint pain; and sore throat.
What Do I Need to Know?
Exdensur is given as an injection under the skin just twice a year. It’s meant to be used as an add-on maintenance therapy along with your regular asthma treatments, not instead of them. It helps prevent severe asthma attacks, but it won’t treat sudden breathing problems associated with asthma, so you’ll still need your rescue inhaler. If a dose is missed, you should contact your health care provider as soon as possible.
If you’re taking steroid medicines (inhalers or tablets) for asthma, don’t change their dose or stop them suddenly when starting Exdensur. Your health care provider will help you lower the dose slowly if needed. Inform your health care provider if you’ve had any previous or ongoing parasitic (worm) infection as it is important that you should be treated for it before starting this medicine. Also, tell your health care provider if you’ve had allergic reactions to similar medicines in the past and about all medications, vitamins, or supplements you take to ensure they’re safe.
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.
