FIST, a sword and shield fusokine for cancer immunotherapy.

To antagonize tumor-derived TGFβ contemporaneously to anticancer immunotherapy, we genetically engineered a fusion protein coupling IL-2 and the ectodomain of TGFβ receptor II (Fusion of Interleukin-2 and Soluble TGFβ receptor - a.k.a. FIST). FIST possesses intriguing gain-of-function properties and induces potent activation of IL2-receptor expressing cells and inhibits tumor-derived angiogenesis. Thus FIST constitutes a first-in-class biological that couples anti-angiogenesis to an immune antitumor response.