INBRX-121

INBRX-121 is an investigational **molecular targeted cytokine** developed by **Inhibrx** for cancer immunotherapy. It is a biologic engineered to deliver a detuned interleukin-2 payload selectively to **natural killer cells** through binding to **NKp46**, an NK cell surface receptor that remains expressed on tumor-infiltrating NK cells. By concentrating reduced-affinity IL-2 signaling on NK cells, INBRX-121 is designed to expand and activate NK-cell populations, enhance cytotoxic function, and improve anti-tumor activity while limiting liabilities associated with conventional IL-2 therapy such as regulatory T-cell expansion and vascular leak syndrome. Publicly available information indicates preclinical anti-tumor activity as both monotherapy and in combination with ADCC-competent antibodies and checkpoint inhibitors, with development reported in the preclinical stage.