Here’s an interesting fact- only about 5% of patients with asthma are classified as severe, yet half of the health spending for asthma comes from this small subset. Why is this the case? Severe asthma is characterized by the lack of response to high doses of inhaled or systemic glucocorticoids, the gold-standard therapy for asthma. As a result, these patients have poorly controlled or uncontrolled asthma, resulting in more hospitalizations and complications. This has been the driving force to find better ways of treating those with severe asthma, and now with the development of new injectable asthma medicines, this group may finally breathe easier.
Asthma injections work differently than traditional asthma drugs.
This new form of asthma treatment stems from the advancements made in biologic therapy, or simply “biologics.” Biologics are made as part of a complex process using living sources, such as human or animal proteins. In contrast, drugs are made in a lab by combining man-made chemicals in a particular order. Both biologics and drugs can be used to prevent, treat, or cure medical conditions.
Their mechanism of action is different, however. For example, asthma patients are generally treated with inhaled glucocorticoids to reduce inflammation that is present in the airways. A biologic asthma injection works to prevent the inflammation from occurring in the first place. This is because a biologic can target specific points in the body’s inflammatory response and alter it at a cellular level.
With the help of injectable asthma medicines, some patients with severe asthma are experiencing an improvement in symptoms that they had previously been unable to achieve.
Not all asthma injections are the same.
We now know that asthma has several different subtypes, based on what triggers it and what response occurs in the body. Researchers use that information to develop asthma medications that are tailored to these subtypes to more effectively treat it. There are currently a few asthma injections on the market.
Immunoglobulin E (IgE) inhibitors: Many people with asthma have allergic asthma. For this group, exposure to certain things in the environment, like animal dander or pollen, causes the immune system to overreact and produce antibodies called IgE. IgE initiates a chain reaction in the body, leading to inflammation in the airways. Omalizumab (Xolair) is an injection that blocks IgE. It can be given every 2 to 4 weeks and may be used for patients over 6 years old.
Anti-interleukin-5 (IL-5)- A type of white blood cell called an eosinophil plays a role in airway inflammation for some asthmatics. An antibody, IL-5, regulates the number of eosinophils. By blocking IL-5, the number of eosinophils are decreased, thereby also decreasing airway inflammation. Two anti-IL-5 injectable medications are available- reslizumab (Cinqair) and mepolizumab (Nucala). Reslizumab is given once every 4 weeks by an infusion into a vein for patients over 18 years old. Mepolizumab is given as an injection once every 4 weeks in patients older than 12.
All injectable asthma medications are given as an add-on to other asthma treatments.
Expect to see more injectable asthma medicines in the future.
The success of these initial injectable asthma medications solidifies the trend toward more personalized asthma treatment. Researchers are continuing to investigate new biologic therapies, and as this happens, we will likely see more injectable asthma medications released to the public. Benralizumab, another anti-IL-5 is undergoing clinical trials, but has not yet received FDA-approval. Other medications are being studied that target IL-3 and IL-14. Researchers are also trying to develop asthma treatments that target multiple proteins at the same time.
Talk to your doctor to find out if asthma injections are right for you.
If you suffer from severe asthma, you may be a good candidate for one of these treatments. As with any medical treatment, there is a potential for side effects and/or severe reactions, so make sure to ask what to watch for. In general, biologics tend to be expensive, so it is also important to find out if your asthma injections would be covered by insurance and what you would pay out of pocket.
