FDA Approves Biosimilar for Omalizumab (Xolair®)

The first biosimilar medication for allergic and respiratory conditions is now available in the United States. On March 7, 2025, the U.S. Food and Drug Administration (FDA) approved Omlyclo® (omalizumab) as the first interchangeable biosimilar for Xolair® (omalizumab).

A biosimilar is essentially a copy of a biologic drug. The active ingredients are the same. Some inactive ingredients may differ, but these are minor.

Omlyclo is manufactured by Celltrion. Like Xolair, it is approved to treat:

• moderate to severe persistent asthma in adult and pediatric patients ages 6 and older
• chronic rhinosinusitis with nasal polyps (CRSwNP) in patients ages 18 and older
• chronic spontaneous urticaria (CSU), also called chronic idiopathic urticaria (CIU), in patients ages 12 and older
• IgE-mediated food allergy in patients ages 1 and older

It is not approved to treat:

• an asthma attack
• anaphylaxis, a severe allergic reaction
• other types of chronic urticaria (chronic hives)

Biosimilars go through FDA review. They must be proven safe and effective before reaching the U.S. market. People taking biosimilars get the same effect of the medication as they do when taking biologics.

What is the benefit of a biosimilar vs. biologic?

Biosimilars are typically more affordable treatment option for patients than most biologics. They take less time, money and research in the development and production process.

Biosimilars increase access to people who need more advanced treatments for these conditions. They are especially beneficial for people in under-resourced communities. This includes people on low income who cannot afford biologics.

Biosimilars can also reduce overall healthcare costs.

Many insurance plans cover biosimilar medications. But coverage may vary between health plans. Talk to your insurance provider about your coverage and treatment options for Omlyclo.

How does Omlyclo work?

As a biosimilar, Omlyclo works the same as Xolair. It targets immunoglobulin E (IgE) antibodies in the immune system.

Many people with asthma, CRSwNP, food allergy and CSU see increased levels of IgE when exposed to an allergen. Omlyclo prevents IgE from binding to receptors of mast cells and basophils. This stops the release of the chemical histamine, a key trigger of symptoms. It also can reduce levels of histamine in the body.

Omlyclo can be used as an add-on medication. This means it can be taken alongside other prescribed medications to treat these conditions.

How is Omlyclo given?

Omlyclo is given as an injection into the skin. This is usually done in a doctor’s office every 2-4 weeks. (The first dose is always done in the doctor’s office.) Patients have the option of self-administering Omlyclo at home using an injectable pen.

The dosing instructions and schedule differ for each condition that Omlyclo treats.

If you’re prescribed Omlyclo, work together with your doctor on a complete treatment plan. You may need regular appointments with your doctor to ensure the treatment is effective.

What are the potential side effects for Omlyclo?

Omlyclo comes with a boxed warning for anaphylaxis, a potentially severe or life-threatening allergic reaction to the medication. This occurs in rare cases. If you’re prescribed Omlyclo, you should have immediate access to epinephrine, the first-line emergency treatment for anaphylaxis.

Side effects may include injection site reactions, joint pain, fever, skin rash and itchiness, headache, dizziness and fatigue. Children may develop an ear infection, upper abdominal pain, and nose bleeds. Evaluate the safety risk of these potential side effects when discussing Omlyclo with your doctor.