SL-115154 CSF1R-Fc-CD40L

SL-115154 is a best-in-class bi-functional fusion protein that sequesters CSF1 in the serum and activates CD40 on immune cells. The ARC consists of CSF1R linked to CD40L, providing checkpoint blockade (CSF1R axis) and potent costimulation (CD40 axis). CSF1 binds to CSF1R on macrophages and induces a significant differentiation into a pro-tumor macrophage phenotype. By sequestering the CSF1 in serum, macrophages will not differentiate and will instead be activated through CD40 to secrete pro-inflammatory cytokines that will help process antigens and activate T and B cells against cancer antigens.