IOS-1002

IOS-1002 (formerly iosH2) is a first-in-class checkpoint inhibitor designed to treat advanced solid tumors and hematologic malignancies. It is a multi-functional fusion protein based on a naturally occurring human leukocyte antigen (HLA), engineered to bind and block the activation of specific immune checkpoint receptors—leukocyte immunoglobulin-like receptor B1 (LILRB1/ILT2), leukocyte immunoglobulin-like receptor B2 (LILRB2/ILT4), and killer cell immunoglobulin-like receptor 3DL1 (KIR3DL1)—on innate and adaptive immune cells. By inhibiting these receptors, which normally suppress immune responses, IOS-1002 reprograms the tumor microenvironment, promoting infiltration by M1 macrophages, T cells, and NK cells to enhance anti-tumor immunity. The drug is being developed as both monotherapy and in combination with PD-1 inhibitors such as pembrolizumab for patients who are non-responsive or have progressed on other adaptive immunity agents[1][3][9].