• Omlyclo is interchangeable with Xolair to treat the same conditions.
• Three FDA-approved doses/solutions of Omlyclo are now available.

The Xolair/omalizumab biosimilar Omlyclo, FDA approved for the treatment of four allergic and inflammatory conditions, is commercially available in the U.S., according to a press release.

“Biologics have changed what is possible for patients with allergic and inflammatory diseases, but they are also some of the most expensive medicines in the U.S. health system,” Juby Jacob-Nara, MD, DHSc, MPH, MBA, senior vice president and chief medical officer at Celltrion USA, told Healio. “That cost reaches patients through prior authorizations, step therapy and high out-of-pocket costs, and for some it means delayed or interrupted treatment.

“Biosimilars bring competition to established biologics, which can lower costs for health plans and health systems and free up resources to treat more patients,” Jacob-Nara said. “Omlyclo gives clinicians and health plans a proven omalizumab option at a time when access to biologics is still a real challenge for many patients.”

As Healio previously reported, the FDA approved Omlyclo (omalizumab-igec, CT-P39; Celltrion) 75 mg/0.5 mL and 150 mg/mL in March 2025 for the treatment of the same conditions as omalizumab (Xolair; Genentech, Novartis):

• moderate to severe persistent asthma in people aged 6 years and older;
• IgE-mediated food allergy in people aged 1 year and older;
• chronic spontaneous urticaria (CSU) in people aged 12 years and older; and
• chronic rhinosinusitis with nasal polyps in adults aged 18 years and older.

A higher 300 mg/2 mL dose was approved for the conditions above in December 2025. Each dosage comes in a single-dose prefilled syringe, according to the release.

“FDA approved Omlyclo based on a comprehensive data package of analytical, nonclinical, pharmacokinetic and clinical data,” Jacob-Nara said. “That package showed Omlyclo is highly similar to Xolair, with no clinically meaningful differences in safety, efficacy, purity or potency.”

In addition to being a biosimilar, Jacob-Nara highlighted that Omlyclo is interchangeable with Xolair.

“[This] means a pharmacist may substitute it for Xolair without the prescriber's intervention, subject to state pharmacy laws,” Jacob-Nara said.

In a multicenter, double-blind, randomized, active-controlled, parallel-group, phase 3 study, researchers evaluated 619 patients with CSU still symptomatic on second-generation H1-antihistamines to determine how add-on 150 mg and 300 mg Omlyclo compares with 150 mg and 300 mg Xolair in weekly itch severity score (ISS7) at week 12.

Between baseline and week 12, the change in ISS7 in the 300 mg Omlyclo group did not differ from the change in the 300 mg Xolair group.

In this same study, Jacob-Nara said, “Omlyclo demonstrated equivalent efficacy and comparable pharmacokinetics, pharmacodynamics, safety and immunogenicity vs. Xolair after 24 weeks of treatment, or after switching from Xolair to Omlyclo at week 12.”

The similarities between Omlyclo and Xolair across various outcomes continued over an additional 16 weeks, according to Jacob-Nara.

“Efficacy, pharmacokinetic, pharmacodynamic, safety and quality of life outcomes of patients treated with Omlyclo were similar to those of patients treated with Xolair through week 40, which included 16 weeks of follow-up after completion of the 24-week treatment period,” she told Healio.

“We look forward to working with the allergy and immunology community, health plans, patient advocacy groups and pharmacists to help more eligible patients get access to this treatment,” Jacob-Nara added.

Juby Jacob-Nara, MD, DHSc, MPH, MBA, can be reached at allergy@healio.com.