FDA Clears 300mg Dose of Celltrion's Xolair Biosimilar OMLYCLO

Celltrion has secured U.S. Food and Drug Administration approval for a new, higher-strength version of OMLYCLO (omalizumab-igec), the company announced on December 3, 2025. The regulator cleared a 300 mg/2mL solution delivered in a single-dose prefilled syringe for subcutaneous injection, adding to the doses already available in the United States.

OMLYCLO is the first and only biosimilar designated by the FDA as interchangeable with XOLAIR, the reference omalizumab therapy marketed by Genentech and Novartis. Interchangeability is a status that can allow a pharmacist to substitute the biosimilar for the branded drug without a new prescription from the treating physician, subject to state rules.

The new 300mg option is designed to cut the number of injections some patients need. Juby Jacob-Nara, Senior Vice President and Chief Medical Officer at Celltrion USA, said the added dose can help reduce the number of required injections and ease the treatment burden for patients.

The FDA first approved OMLYCLO in March 2025 in 75 mg/0.5mL and 150 mg/mL formulations. The therapy is indicated for moderate to severe persistent asthma, chronic rhinosinusitis with nasal polyps, immunoglobulin E (IgE)-mediated food allergy, and chronic spontaneous urticaria.

The wider dosing range strengthens Celltrion's foothold in the U.S. immunology market, where the company has been building out a lineup of biosimilars referencing high-value biologic medicines. Omalizumab treatments target patients whose allergic and inflammatory conditions are driven by IgE antibodies.

Biosimilars are approved to be highly similar to an existing biologic with no clinically meaningful differences, and they are widely viewed as a way to broaden patient access and lower costs. For Celltrion, the expanded OMLYCLO franchise adds another commercial lever as it competes against branded biologics in one of the world's largest drug markets.