Celltrion announced on March 11 that it has completed the application process for U.S. Food and Drug Administration (FDA) approval of “CT-P39,” a biosimilar to the asthma and chronic idiopathic urticaria treatment XOLAIR. The company applied for product approval based on the results of a global Phase 3 clinical trial involving 619 patients with Chronic Spontaneous Urticaria (CSU), covering major indications such as asthma, chronic rhinosinusitis, food allergies, and chronic idiopathic urticaria.
In the clinical trial, participants were divided into two groups: those receiving CT-P39 and those receiving XOLAIR, at doses of 300mg and 150mg. The primary endpoint was the change in the Weekly Itch Severity Score (ISS7) at week 12 compared to baseline. CT-P39 met the predefined criteria for equivalence and showed similar results to the original medication in secondary endpoints such as safety and immunogenicity evaluations.
Prior to this application for U.S. approval, Celltrion had completed applications for approval in Europe, Canada, and South Korea last year. Notably, the U.S. application is being processed as an “interchangeable” biosimilar, which, upon approval, would allow for quick market expansion due to its eligibility for substitution in place of the original product.
The original drug, XOLAIR, reported global sales of approximately 5 trillion won in 2023. Its substance patent has already expired, with the formulation patent set to expire in Europe in March 2024 and in the U.S. in November 2025.