CUE-221

CUE-221 is a clinical-stage anti-IgE monoclonal antibody being developed by Cue Biopharma for the treatment of allergic diseases, including food allergy and chronic spontaneous urticaria (CSU). Licensed from Ascendant Health Sciences (where it was known as UB-221), the drug features a novel dual mechanism of action. It neutralizes free IgE to block allergic signaling and simultaneously leverages the CD23-mediated IgE downregulation pathway to suppress IgE mRNA and protein synthesis. This approach aims to provide more potent and durable IgE suppression compared to first-generation anti-IgE therapies by not only clearing circulating IgE but also inhibiting its production at the source.