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Understanding Asthma

Asthma is more than just coughing or wheezing. It’s a chronic (long-term) lung disease that can deeply affect your everyday life. Whether your symptoms are new or you’ve been living with asthma for years, it helps to understand what’s really going on in your body, which may help you navigate your journey.

About Asthma

Asthma is a chronic, inflammatory lung disease linked to your immune system. It causes the airways in your lungs to become swollen and inflamed, making it harder to breathe.1

There are many different types of asthma, and asthma can look different for everyone. Asthma can start in childhood or adulthood and change over time. It can be mild or severe, even life-threatening if not managed properly. It can’t be cured, but it can often be managed with the right care.1

Your doctor can do tests to help figure out what kind of asthma you have and what treatments might work best for you.

1 in 30
people around the world have asthma2 
A woman with a hand on her chest feeling her breath.

Symptoms may resemble other lung conditions, called asthma mimics, and can be misdiagnosed as a result. It’s important to speak with your doctor about your symptoms.3

Asthma symptoms include:

  • Coughing, often worse at night or early morning
  • Shortness of breath
  • Chest tightness or pain
  • Wheezing (a whistling sound when you breathe out)1,3

Some people experience occasional symptoms. Others live with more frequent flare-ups, called asthma attacks, when breathing becomes more difficult quickly. It can be scary and dangerous.1

If attacks happen often — even while taking medication — or you find yourself frequently using your rescue inhaler, waking up at night, or avoiding activities you used to love to do, you may have uncontrolled or a more severe form of asthma.4,5

Even if symptoms look the same, asthma can be set off by different things in different people. These are called triggers. Knowing your triggers can help you manage your asthma.

Common asthma triggers include:

  • Allergens (such as pollen, dust mites, mold or pet dander)
  • Infections (like colds or the flu)
  • Weather changes or cold air
  • Pollution or poor air quality
  • Strong emotions or stress
  • Certain medicines7
Asthma insights

Your Immune System and What Causes Asthma

Doctors now understand that asthma isn’t just about symptoms or triggers. It’s also about how your immune system behaves inside your body.7

Your immune system is your body’s defense team. It helps protect you from things that can make you sick. But in asthma, your immune system overreacts. This causes inflammation in your lungs. Your airways become narrower and fill with mucus. That’s what makes it hard to breathe.1,6

No one knows exactly what causes asthma. But doctors think it’s a mix of genetic and environmental factors. Family history, infections in childhood, and exposure to pollution may all play a role in how your immune system forms.3,6

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Learning about endotypes

Types of Asthma 

Because asthma involves the immune system, doctors have found different ways it shows up in the body. They now group asthma into categories called endotypes. These are based on which parts of the immune system show up, not just what symptoms or triggers you have.4,8

One endotype is called Type 2-high asthma.9 It’s more common in moderate-to-severe asthma. You may have heard of it if you’ve been diagnosed with eosinophilic asthma, a more severe form often seen in adults. People in this group may also experience related conditions like atopic dermatitis, nasal polyps or chronic sinus issues.4,5

Endotypes help explain why asthma can be harder to control in some people. Knowing your asthma type can help personalize your treatment plan. Ask your doctor about routine blood tests that could help identify your asthma type.9

Endotype
An endotype is a way of describing a disease based on the root cause inside the body, not just the symptoms you can see. 
Type 2-High Asthma
Type 2-high asthma is a form of asthma where the immune system is very active in a certain way, causing more inflammation in the lungs.5 A FeNO test may help with diagnosis.10
Eosinophilic Asthma
Eosinophilic asthma is a subset of Type 2-high asthma. Eosinophils are white blood cells that help fight infection, but too many can cause inflammation, like in asthma or allergies. If you have higher levels of eosinophils, your asthma may be harder to manage with worse symptoms. Your eosinophil levels can also help you and your doctor decide on a treatment.5
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Kymera’s Approach to Developing a Potential Oral Treatment

Kymera is doing research to create an investigational oral medicine (a treatment taken by mouth) for asthma. We aim to develop an effective, safe, easy-to-take pill that lowers the amount of lung inflammation.

Proteins are the building blocks of your body. They help you function and stay healthy. But they can sometimes cause problems in your immune system. Kymera’s medicine is designed to use one of the body’s natural systems to remove unhelpful proteins that might be making your inflammation worse. Our approach is called targeted protein degradation, or TPD.

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Kymera's Clinical Trials

A clinical trial is a research study of people with a condition or disease to test if new medicines are safe and effective. Kymera is conducting clinical trials to test a potential investigational oral medicine for asthma. Talk with your doctor about whether a clinical trial is right for you. Learn more about Kymera’s ongoing trials below.

The safety and efficacy of these investigational agents have not been established. These agents are not approved by any regulatory body for any indication.

KT-621 is an investigational oral degrader in development for the treatment of immunological and inflammatory diseases

RECRUITING
BREADTH Phase 2b in Asthma

The KT-621 BREADTH Phase 2b randomized, double-blind, placebo-controlled, multicenter, dose-ranging trial is evaluating the efficacy, safety, and tolerability of orally administered KT-621 in adult patients with moderate to severe eosinophilic asthma.

Kymera’s investigational drugs are currently at a stage in development where we are focused on enrolling patients in our clinical trials and continuing to learn more about our investigational drugs’ safety and efficacy. At this time, Kymera is not able to make expanded access available to its investigational drugs. For more information, please read our full expanded access policy.

A woman with a child laughing together on a blanket outside.
Living with Asthma 

Asthma can be frustrating or even dangerous. You may feel like you’re doing everything right, but symptoms still get in the way. You may feel tired, misunderstood or embarrassed. You may live in fear of being unable to manage the next attack.11

You’re not wrong. Asthma affects more than just your lungs — it can impact your whole life. Living with or in fear of asthma symptoms can lead to:

  • Poor sleep
  • Anxiety or depression
  • Missing work or school
  • Avoiding social events, exercise or other activities you love5,12,13

But you’re not alone. Understanding your asthma and how it affects your body is a powerful step towards managing it.

References

  1. What Is Asthma? American Lung Association. July 18, 2025. Accessed August 18, 2025. https://www.lung.org/lung-health-diseases/lung-disease-lookup/asthma/learn-about-asthma/what-is-asthma 

  2. The Global Asthma Network. The Global Asthma Report 2022. Int J Tuberc Lung Dis. 2022;26(1):1-104. doi:10.5588/ijtld.22.1010 

  3. Goldin J, Hashmi MF, Cataletto ME. Asthma. In: StatPearls. StatPearls Publishing; 2025. Accessed August 19, 2025. http://www.ncbi.nlm.nih.gov/books/NBK430901/ 

  4. Severe Asthma. American Lung Association. Accessed August 19, 2025. https://www.lung.org/lung-health-diseases/lung-disease-lookup/asthma/learn-about-asthma/types/severe-asthma

  5. When Asthma Is More Than Just Asthma: Type 2 Inflammation. Allergy & Asthma Network. July 19, 2025. Accessed August 19, 2025. https://allergyasthmanetwork.org/news/when-asthma-more-than-asthma-type-inflammation/ 

  6. Asthma – Causes and Triggers. NIH: NHLBI. April 17, 2024. Accessed August 19, 2025. https://www.nhlbi.nih.gov/health/asthma/causes 

  7. Hammad H, Lambrecht BN. The basic immunology of asthma. Cell. 2021;184(6):1469-1485. doi:10.1016/j.cell.2021.02.016 

  8. Types of Asthma. American Lung Association. Accessed August 19, 2025. https://www.lung.org/lung-health-diseases/lung-disease-lookup/asthma/learn-about-asthma/types 

  9. Kuruvilla ME, Lee FEH, Lee GB. Understanding Asthma Phenotypes, Endotypes, and Mechanisms of Disease. Clin Rev Allergy Immunol. 2019;56(2):219-233. doi:10.1007/s12016-018-8712-1 

  10. What is FeNO in Asthma? Allergy & Asthma Network. Accessed October 15, 2025. https://allergyasthmanetwork.org/what-is-asthma/how-is-asthma-diagnosed/nitric-oxide-testing/ 

  11. My Life with Asthma Survey Findings Report. Asthma and Allergy Foundation of America; 2017:1-16. 

  12. Freitas J, Novais F. Review on the relationship of asthma and mental disorders. Pers Med Psychiatry. 2025;51-52:100157. doi:10.1016/j.pmip.2025.100157 

  13. Katsaounou P, Odemyr M, Spranger O, et al. Still Fighting for Breath: a patient survey of the challenges and impact of severe asthma. ERJ Open Res. 2018;4(4):00076-02018. doi:10.1183/23120541.00076-2018