APN-541885

APN-541885 is an orally bioavailable small molecule inhibitor of Cbl-b (Casitas B-lineage lymphoma proto-oncogene b), an E3 ubiquitin ligase that serves as a critical intracellular checkpoint in immune cells. Cbl-b negatively regulates the activation of T cells and natural killer (NK) cells by promoting the ubiquitination and subsequent degradation of key signaling molecules. By inhibiting Cbl-b, APN-541885 enhances immune cell sensitivity to antigens and reduces the threshold for activation, thereby promoting a robust anti-tumor immune response. Developed by Apeiron Biologics (now Invincity), this agent is being investigated for its potential to treat various solid tumors, either as a monotherapy or in combination with other immunotherapies.