XmAb24306

XmAb24306 (also known as AMG 592) is an investigational bispecific cytokine-Fc fusion protein designed to act as a long-acting interleukin-15 (IL-15) receptor agonist. Developed by Xencor in collaboration with Amgen, the molecule consists of an IL-15 cytokine domain and an IL-15 receptor alpha (IL-15Rα) sushi domain fused to a heterodimeric Fc region using Xencor's proprietary XmAb technology. This design mimics the natural 'trans-presentation' of IL-15, where IL-15 is presented by IL-15Rα to the IL-15Rβ/γ complex on effector cells. By incorporating a modified Fc region, XmAb24306 exhibits a significantly extended half-life compared to recombinant human IL-15 and is engineered to reduce binding to the high-affinity IL-15Rα on regulatory T cells, thereby preferentially stimulating cytotoxic T cells and natural killer (NK) cells. It was primarily evaluated for the treatment of advanced solid tumors and systemic lupus erythematosus (SLE), though its development was discontinued by Amgen in 2022.

Other names

interleukin-15/Fc bispecific fusion proteinIL-15/IL-15Rα-Fc fusion proteinIL-15/Fc bispecific