Celltrion USA's Omlyclo, the first interchangeable biosimilar to Xolair, reaches the U.S. market across four allergic and inflammatory indications.
Celltrion USA announced Oct. 5 that Omlyclo (omalizumab-igec), the first biosimilar to Xolair (omalizumab) that the FDA has designated as interchangeable, is now commercially available in the United States.1 The product is supplied as a single-dose prefilled syringe for subcutaneous injection in 75 mg/0.5 mL, 150 mg/mL and 300 mg/2 mL strengths.1
The company said FDA approval came in March 2025.1 For payers and health systems, the open question is whether an interchangeable biosimilar can improve affordability of a biologic whose cost, according to Dr. Juby Jacob-Nara, senior vice president and chief medical officer at Celltrion USA, has constrained access.
“Yet the high cost of biologic therapies has limited access for many patients, creating challenges for both individuals and the healthcare system,” she said.1
Omlyclo carries the same four indications as its reference product: moderate to severe persistent asthma in patients 6 and older, chronic rhinosinusitis with nasal polyps in adults 18 and older, immunoglobulin E (IgE)-mediated food allergy in patients 1 and older, and chronic spontaneous urticaria (CSU) in patients 12 and older who remain symptomatic despite H1 antihistamine treatment.1,2
The label carries a boxed warning for anaphylaxis, directs that therapy begin in a healthcare setting and states the product is not for emergency treatment of allergic reactions.2 The European Medicines Agency lists a marketing authorization valid across the European Union from May 16, 2024.3
Dr. Michael S. Blaiss, clinical professor of pediatrics at the Medical College of Georgia at Augusta University, described how broadly the drug is used in allergy practice.
“In allergy practice, omalizumab is used across conditions that can look very different from one patient to the next, from uncontrolled allergic asthma and nasal polyps to food allergy and chronic hives,” he said. “The availability of Omlyclo gives clinicians the first interchangeable omalizumab biosimilar option, now with a 300 mg prefilled syringe alongside the 75 mg and 150 mg presentations.”1
The comparative study was a double-blind, randomized, active-controlled phase 3 trial in 619 patients with CSU. Participants received the investigational antibody, then called CT-P39, or European Union-approved reference omalizumab at 150 mg or 300 mg.4 The primary endpoint was change from baseline in weekly itch severity score at week 12, compared between the 300 mg arms, which enrolled 204 patients on CT-P39 and 205 on the reference product.4
Investigators reported equivalent efficacy and comparable safety.4 In a second 12-week period, patients who had received reference omalizumab at 300 mg were re-randomized to continue it or switch to CT-P39, allowing comparison of continued and switched therapy.4
Omalizumab is a humanized IgG1 kappa monoclonal antibody that binds IgE. In asthma, nasal polyps and food allergy, it inhibits IgE binding to its high-affinity receptor on mast cells, basophils and dendritic cells.2 In CSU, the label states that how these effects improve symptoms is unknown.2
The label positions the drug for patients whose disease persists despite standard therapy: asthma inadequately controlled with inhaled corticosteroids, nasal polyps with inadequate response to nasal corticosteroids, and urticaria that remains symptomatic on antihistamines.2
The label describes Omlyclo as a recombinant antibody produced in Chinese hamster ovary cell suspension culture, manufactured by Celltrion, Inc., in Incheon, Republic of Korea, and distributed by Celltrion USA from Jersey City, New Jersey.2
Prefilled syringes are shipped and stored at 2 °C to 8 °C, with total time out of the refrigerator limited to seven days.2 Celltrion’s U.S. portfolio spans biosimilars in immunology, oncology, hematology, endocrinology and ophthalmology, according to the release.1
Thomas Nusbickel, chief commercial officer at Celltrion USA, tied the launch to the company’s manufacturing record.
“Biosimilars have become an established part of care across therapeutic areas including oncology, rheumatology, and gastroenterology,” he said. “Now, we have the opportunity to bring that same experience and benefits to allergy and immunology. For Celltrion, this is more than entering a new category – it is about applying the manufacturing discipline, quality focus and commercial infrastructure we have built over more than two decades to make an additional omalizumab option available to U.S. patients and their care teams.”1
The announcement does not provide pricing, payer coverage, supply volumes or the timing of availability for each strength relative to the March 2025 approval.1 The published comparative trial evaluated CSU only; for pediatric use in asthma, food allergy and CSU, the label states support comes from studies of omalizumab itself.2,4
The label also notes that malignancies were observed in omalizumab clinical studies and that the effect of longer exposure is not known.2 The “first and only” designation reflects the company’s characterization.
1. OMLYCLO (omalizumab-igec), the first and only FDA-approved interchangeable biosimilar to XOLAIR, now commercially available in the U.S. News release. Celltrion USA, Inc. October 5, 2026. Accessed October 7, 2026. https://www.prnewswire.com/news-releases/omlyclo-omalizumab-igec-the-first-and-only-fda-approved-interchangeable-biosimilar-to-xolair-now-commercially-available-in-the-us-302898400.html
2. Omlyclo. Prescribing information. Celltrion, Inc; revised December 2025. Accessed October 7, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/761399s004lbl.pdf
3. Omlyclo. European public assessment report. European Medicines Agency. Accessed October 7, 2026. https://www.ema.europa.eu/en/medicines/human/EPAR/omlyclo
4. Saini SS, Maurer M, Dytyatkovska Y, et al. CT-P39 compared with reference omalizumab in chronic spontaneous urticaria: results from a double-blind, randomized, active-controlled, phase 3 study. Allergy. 2025;80(8):2167-2177. doi:10.1111/all.16446
