Definition

A recombinant fusion protein comprised of a human monoclonal antibody directed against fibroblast activation protein-alpha (FAP) linked to an engineered, variant form of interleukin-2 (IL-2v), with potential immunostimulating and antineoplastic activities. Upon administration of simlukafusp alfa, the monoclonal antibody moiety recognizes and binds to FAP, thereby concentrating IL-2 in FAP-expressing tumor tissue. Subsequently, the IL-2 moiety of this fusion protein may stimulate a local immune response and activate natural killer (NK) cells and cytotoxic T cells. FAP is a cell surface protein that is expressed on a wide variety of cancer cells. IL-2v cannot bind to IL-2 receptor-alpha (CD25, IL2Ra) and does not activate regulatory T cells (Tregs).