No abstract

The delivery of specific cytokine payloads to a neoplastic environment employing antibodies able to selectively accumulate at the tumor site represents an attractive strategy to stimulate an immune response to cancer. Whilst conventional antibody–cytokine fusions based on a single payload have shown potent anticancer activity, the concomitant delivery of two cytokine payloads may further improve the therapeutic outcome as the immune system typically adopts multiple signals to reinforce an antitumor strategy. We here describe a potency-matched dual-cytokine antibody fusion protein containing a tumor-targeting antibody fragment specific to human fibroblast activation protein (FAP), simultaneously linked to both interleukin-2 (IL2) and a tumor necrosis factor (TNF) mutant. The resulting fusion protein, termed IL2-7NP2-TNFmut, formed stable non-covalent trimers driven by the interaction of the tumor necrosis factor subunits. Both cytokine payloads retained their biological activity within the fusion protein, as shown by in vitro cellular assays. The tumor-targeting properties and the anticancer activity of IL2-7NP2-TNFmut were investigated in vivo in immunocompromised mice bearing SKRC52 cells transduced with human FAP. The fusion protein preferentially localized to the cancer site and induced partial tumor retardation.

Natural Killer Group 2D (NKG2D) is a homo‐dimeric transmembrane protein which is typically expressed on the surface of natural killer (NK) cells, natural killer T (NKT) cells, gamma delta T (γδT) cells, activated CD8 positive T‐cells and activated macrophages. Bispecific molecules, capable of bridging NKG2D with a target protein expressed on the surface of tumor cells, may be used to redirect the cytotoxic activity of NK‐cells towards antigen‐positive malignant T‐cells. In this work, we report the discovery of a novel NKG2D small molecule binder [KD=(410±60) nM], isolated from a DNA‐Encoded Chemical Library (DEL). The discovery of small organic NKG2D ligands may facilitate the generation of fully synthetic bispecific adaptors, which may serve as an alternative to bispecific antibody products and which may benefit from better tumor targeting properties.