Alomfilimab is an investigational monoclonal antibody targeting ICOS (Inducible T-cell CO-Stimulator), also known as CD278, a protein expressed on activated T cells, particularly regulatory and follicular helper T cells. Its primary application lies in immuno-oncology, where it is being explored to modulate the immune response against tumors. By blocking ICOS, alomfilimab may inhibit the activity of immunosuppressive regulatory T cells within the tumor microenvironment, thereby enhancing anti-tumor immunity. It has been evaluated in clinical trials, often in combination with other immunotherapies such as anti-PD-1 or anti-CTLA-4 antibodies, to improve response rates in cancers like melanoma, non-small cell lung cancer, and other solid tumors. Additionally, due to ICOS's role in autoimmune and inflammatory conditions, alomfilimab may have potential applications in treating autoimmune diseases, though its development has mainly focused on oncology indications.