Clinical outcomes of switching from original omalizumab to an intended-copy biosimilar in chronic urticaria: a case series highlighting global regulatory discrepancies

Omalizumab, an anti-IgE monoclonal antibody, is a standard treatment for chronic spontaneous urticaria (CSU). In India, an ‘intended-copy biosimilar’ (ICB) was introduced in 2020, based on structural similarity, without clinical trials. This case series compares the efficacy and safety of ICBs with the original biologic. A retrospective review of nine patients with CSU (mean age 37.1 years) who switched from omalizumab to an ICB due to the unavailability of omalizumab. Disease control was assessed using the Urticaria Activity Score and the Urticaria Control Test. Findings highlight the need for rigorous biosimilar testing and standardized nomenclature to distinguish biosimilar types.