Biologics for Asthma: What Patients Should Know

Biologics are medications made from living organisms or components of living organisms. In asthma, biologics are usually monoclonal antibodies, which are lab-made antibodies designed to target specific proteins involved in inflammation.

Unlike traditional inhalers, which are breathed into the lungs, asthma biologics are given by injection or infusion. They are designed to reduce specific immune signals that contribute to airway inflammation, asthma symptoms, and asthma flare-ups.

Most asthma treatment starts with inhaled medications.

A rescue inhaler, such as albuterol, works quickly to relax tightened airway muscles during asthma symptoms. Controller inhalers, such as inhaled corticosteroids or combination inhalers, are used regularly to reduce inflammation and help prevent symptoms.

Biologics work differently. They target immune pathways that may be driving inflammation in certain types of asthma. Instead of simply opening the airways during symptoms, biologics are used as long-term controller medications to help reduce the underlying inflammatory process.

Biologics do not replace emergency care, and they do not mean a person can stop carrying a rescue inhaler. Medication changes should always be made with a healthcare provider.

Biologics are generally considered for people with moderate to severe asthma that is not well controlled with standard controller medications.

A provider may consider biologic therapy if a patient has:

• Frequent asthma symptoms
• Frequent rescue inhaler use
• Asthma attacks or flare-ups
• Emergency room or urgent care visits for asthma
• Repeated courses of oral steroids
• Ongoing symptoms despite daily controller inhalers
• Allergic asthma, eosinophilic asthma, steroid-dependent asthma, or another severe asthma pattern

Before recommending a biologic, a provider may review symptom history, lung function testing, allergy testing, blood work, eosinophil levels, IgE levels, medication history, and other health conditions.

Different biologics target different immune pathways. This is why identifying the type of asthma a person has is important.

Some biologics are used for allergic asthma. Others are used for eosinophilic asthma. Some may be used for broader severe asthma patterns.

Omalizumab / Xolair

Omalizumab, sold under the brand name Xolair, is used for certain patients with moderate to severe allergic asthma.

Allergic asthma is asthma driven by allergic triggers. Patients who may be considered for omalizumab usually need evidence of sensitivity to a year-round allergen, such as dust mites, mold, cockroach, cat, dog, or other perennial allergens. A provider may also check total IgE levels through blood work.

IgE is often called the allergy antibody. In allergic asthma, IgE can attach to immune cells and contribute to the release of inflammatory chemicals. Omalizumab works by targeting IgE, helping reduce allergic inflammation that may contribute to asthma symptoms.

Omalizumab may also be used for other allergic conditions, including chronic spontaneous urticaria and chronic rhinosinusitis with nasal polyps, depending on the patient and indication.

Eosinophils are a type of white blood cell involved in the immune system. In some people with asthma, eosinophils contribute to airway inflammation and asthma attacks. This is often called eosinophilic asthma.

A provider may check a blood eosinophil count when evaluating whether a patient may be a candidate for certain biologics.

Mepolizumab / Nucala

Mepolizumab, sold under the brand name Nucala, targets interleukin-5, also known as IL-5.

IL-5 is a protein involved in the growth, activation, and survival of eosinophils. By blocking IL-5, mepolizumab can help reduce eosinophil-driven inflammation in patients with severe eosinophilic asthma.

Mepolizumab may also be used for certain other eosinophilic or inflammatory conditions, depending on the diagnosis.

Reslizumab / Cinqair

Reslizumab, sold under the brand name Cinqair, is another biologic that targets the IL-5 pathway.

Unlike many asthma biologics that are injected under the skin, reslizumab is given by IV infusion. Because of that, it must be administered in a medical setting that can provide infusion therapy.

This may be an important consideration for patients when choosing between biologic options.

Benralizumab / Fasenra

Benralizumab, sold under the brand name Fasenra, targets the IL-5 receptor. By acting on this receptor, it helps reduce eosinophils that contribute to airway inflammation.

Benralizumab is used for severe eosinophilic asthma in eligible patients. It is typically given as an injection, and after the initial doses, some patients may move to less frequent dosing.

Dupilumab / Dupixent

Dupilumab, sold under the brand name Dupixent, targets pathways involving IL-4 and IL-13. These immune signals are involved in type 2 inflammation, which can contribute to asthma, eczema, nasal polyps, and other allergic or inflammatory conditions.

Dupilumab may be considered for certain patients with eosinophilic asthma or steroid-dependent asthma. It may also be helpful in patients who have asthma along with other type 2 inflammatory conditions, such as atopic dermatitis or chronic rhinosinusitis with nasal polyps.

Tezepelumab / Tezspire

Tezepelumab, sold under the brand name Tezspire, targets thymic stromal lymphopoietin, also known as TSLP.

TSLP is involved early in the inflammatory process that can lead to asthma symptoms and flare-ups. Because tezepelumab works higher up in the inflammatory pathway, it may be considered for certain patients with severe asthma who do not fit neatly into allergic or eosinophilic categories.

This makes it different from biologics that require specific allergic or eosinophilic markers.

Depemokimab / Exdensur

Depemokimab, sold under the brand name Exdensur, is a newer biologic approved for severe eosinophilic asthma in eligible patients. It targets the IL-5 pathway and is notable because it is designed for less frequent dosing than many other asthma biologics.

Because this is a newer medication, patients should speak with an asthma specialist or allergy/immunology provider to understand whether it may be appropriate for their specific situation.

Asthma biologics are not inhalers. They are usually given as injections under the skin or, in some cases, by IV infusion.

Depending on the medication, biologics may be given:

• At home with an auto-injector or prefilled syringe
• In a doctor's office
• In an infusion center
• Every 2 weeks, 4 weeks, 8 weeks, or at another dosing interval depending on the medication

Some biologics require initial monitoring in a medical office because of the possibility of an allergic reaction. Your provider will explain how your specific medication is given and whether any observation period is needed.

No. Biologics do not cure asthma.

Asthma is usually a chronic condition. Biologics are designed to help control certain types of inflammation and reduce the risk of symptoms or flare-ups in eligible patients.

Some patients may be able to reduce other asthma medications over time if their asthma becomes better controlled, but this should only be done under medical supervision.

Patients using biologics should still follow their asthma action plan and carry their rescue inhaler unless their provider gives different instructions.

Choosing the right biologic depends on several factors. A provider may consider:

• Asthma severity
• How often symptoms occur
• Rescue inhaler use
• Emergency visits or hospitalizations
• Oral steroid use
• Allergy testing results
• Total IgE level
• Blood eosinophil count
• FeNO testing, if available
• Other conditions such as eczema, chronic hives, nasal polyps, or eosinophilic esophagitis
• Age eligibility
• Dosing schedule
• Whether the medication is injected or infused
• Patient comfort with home injections
• Insurance coverage

This decision is usually made through shared decision-making between the patient and provider. That means the provider explains the options, risks, benefits, and practical considerations, and the patient is involved in choosing the treatment plan.

Each biologic has its own side effect profile. Common side effects may include:

• Injection site redness, itching, swelling, or discomfort
• Headache
• Fatigue
• Sore throat
• Joint pain
• Back pain
• Cold-like symptoms
• Eye irritation with some medications
• Rare allergic reactions

Some biologics may require additional precautions for certain patients. For example, providers may ask about parasitic infections before using medications that affect eosinophils, because eosinophils play a role in the body's response to some parasites.

Patients should review their full medical history with a healthcare provider before starting biologic therapy.

If your asthma is not well controlled, ask your provider:

• What type of asthma do I have?
• Is my asthma considered moderate or severe?
• Do I have allergic asthma, eosinophilic asthma, or type 2 inflammation?
• Should I have allergy testing?
• Should I have blood work to check IgE or eosinophil levels?
• Am I using my current inhalers correctly?
• Do I need a controller medication adjustment before considering a biologic?
• Which biologics could I be eligible for?
• How often would the medication be given?
• Would I take it at home or in the office?
• What side effects should I know about?
• Would I still need my inhalers?
• How will we know if the biologic is working?
• How long should we try it before deciding whether to continue?

You may want to ask about biologics if your asthma continues to interfere with daily life despite treatment.

Signs that asthma may not be well controlled include:

• Symptoms more than a couple of times per week
• Waking up at night because of asthma
• Frequent rescue inhaler use
• Limiting activity because of breathing symptoms
• Repeated oral steroid prescriptions
• ER or urgent care visits for asthma
• Asthma symptoms triggered by allergies despite treatment

Biologics are not right for everyone, but they can be life-changing for some patients with moderate to severe asthma.