F8-IL2

**F8-IL2** is an investigational tumor-targeted immunocytokine composed of the human F8 antibody fragment in diabody format fused to human interleukin-2. The F8 moiety binds the alternatively spliced extra domain A of fibronectin, an extracellular-matrix marker enriched in tumor stroma and neovasculature, directing IL-2 activity toward tumor tissue. Local IL-2 receptor stimulation promotes antitumor immune activity, including natural killer-cell and cytotoxic CD8-positive T-cell infiltration and activation. F8-IL2 has demonstrated antitumor activity in preclinical models of melanoma, acute myeloid leukemia, lung adenocarcinoma, and renal cell carcinoma, including enhanced activity in combination with chemotherapy, immune-checkpoint blockade, TNF-based immunocytokines, and transient JAK inhibition to mitigate systemic IL-2 toxicity. Publicly available evidence supports a preclinical-stage program rather than a marketed or clinically established product.