sdAb20-Fc

sdAb20-Fc is an AXL-specific single-domain antibody (sdAb) fused to an Fc domain, developed for the treatment and diagnosis of acute myeloid leukemia (AML). Derived from alpacas, the sdAb20 component exhibits cross-reactivity for both human and mouse AXL and high nanomolar affinity. It functions by blocking the interaction between AXL and its ligand, GAS6, thereby inhibiting downstream signaling pathways that promote tumor cell survival and proliferation. In preclinical studies, sdAb20-Fc has demonstrated anti-tumor activity as a monotherapy and synergistic effects when combined with cytarabine. Additionally, the sdAb20 fragment can be radiolabeled (e.g., with 99mTc) for use as a diagnostic imaging agent to identify AXL-positive tumors.