Biosimilar Medication Omlyclo® is Now Available
Published: March 18, 2025 Revised: September 16th, 2026
The first biosimilar medication for respiratory, allergic and inflammatory conditions — Omlyclo® (omalizumab) — is now available in the United States (as of Sept. 1, 2026).
Omlyclo is an interchangeable biosimilar for Xolair® (omalizumab). It is a prescription medication. Omlyclo earned U.S. Food and Drug Administration (FDA) approval on March 9, 2025.
A biosimilar is essentially a copy of a biologic drug. There may be some subtle differences, but the active ingredients are the same.
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 should not be used to treat:
- an asthma exacerbation (attack) or sudden breathing problems
- anaphylaxis, a severe allergic reaction
- other types of chronic urticaria (chronic hives)
Clinical studies have shown that Omlyclo has the same safety and effectiveness profile as Xolair.
Some key differences between Omlyclo and Xolair include:
| Medication Name | Information |
|---|---|
| XOLAIR | Shelf life: 18 months Safe at room temperature: 2 days |
| OMLYCLO | Shelf life: 24 months Safe at room temperature: 7 days |
Just like all medications, biosimilars must earn FDA approval. 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.
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 allergic asthma, CRSwNP, food allergy and CSU see increased levels of IgE when exposed to an allergen. Omlyclo prevents the IgE from binding to the receptors of mast cells and basophils. This stops the release of histamine, a key trigger of symptoms. It also can reduce levels of histamine in the body.
Omlyclo is not used to treat an asthma attack or a flare-up of asthma symptoms.
Omlyclo can be used as an add-on maintenance treatment. This means Omlyclo can be taken alongside other prescribed medications. These include inhaled corticosteroids for asthma or antihistamine treatments for CSU.
How is Omlyclo given?
Omlyclo is given as an injection into the skin from a single-dose prefilled syringe. This is usually done in a doctor’s office every 2-4 weeks. (The first dose is always done in the doctor’s office.) Coming soon, patients will also 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?
As with Xolair, 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 are prescribed Omlyclo, your healthcare provider will monitor you closely for a period of time after treatment.
If symptoms occur, you and/or the clinic should have immediate access to epinephrine, the first-line emergency treatment for anaphylaxis.
Omlyclo 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.
What is the benefit of a biosimilar vs. biologic?
Biosimilars are typically a more affordable treatment option for patients than biologics. They take less time, money and research in the development and production process. This can help reduce overall healthcare costs.
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.
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.
Omlyclo is considered “interchangeable.” This means it has gone through an added FDA review to demonstrate it is highly similar to the original biologic and meets FDA standards for switching. You can switch between the interchangeable biosimilar and the original biologic (Xolair) without any issue.
How much does Omlyclo cost?
The list price for the Xolair biosimilar Omlyclo is not available. Biosimilars typically launch at a discount to their reference brand-name biologics. The exact cost may depend on your insurance.
Celltrion has announced an Omlyclo patient assistance program called Celltrion CARES®. Through its Co-pay Assistance Program, eligible patients who have private or commercial insurance may be able to obtain Omlyclo for as little as $0.
Celltrion Connect® and Celltrion NurseConnector™ are additional patient assistance programs. They provide patients with personalized support.
A Celltrion Connect case coordinator can get you started on Omlyclo, help you navigate insurance coverage, and determine eligibility for financial assistance.
A Nurse Connector is a registered health professional who can provide you with injection training and educational support.
September 2026
Reviewed by:
Purvi Parikh, MD, FACAAI is an adult and pediatric allergist and immunologist at Allergy and Asthma Associates of Murray Hill in New York City. She is on faculty as Clinical Assistant Professor in both departments of Medicine and Pediatrics at New York University School of Medicine.
