LILRB2, also known as ILT4, is expressed mostly by myeloid cells, including monocytes, dendritic cells, macrophages, and neutrophils. In solid tumors, interaction of LILRB2 with tumor microenvironment (TME) relevant ligands, including HLA-G, ANGPTLs, SEMA4A, and CD1d, induces a tolerogenic phenotype in myeloid cells, thereby suppressing T cell activation and promoting tumor immune evasion.

IO-108 is a fully human IgG4 monoclonal antibody with high affinity and specificity towards the myeloid checkpoint, LILRB2 (also known as ILT4). It blocks the interaction of LILRB2 with multiple ligands that are involved in cancer-associated immune suppression, including HLA-G, ANGPTLs, SEMA4A and CD1d.

Clinical data from the U.S. Phase 1 dose escalation study of IO-108 (NCT05054348) was presented at the 2023 American Association for Cancer Research annual meeting and demonstrated a favorable safety profile and encouraging clinical benefit utilizing IO-108 as a monotherapy and in combination with anti-PD-1 across multiple tumor types.

Immune-Onc has established agreements with leading biopharmaceutical companies, including BeiGene and Regeneron, to support its global product development plans for IO-108. A Roche-led, global, randomized Phase 1b/2 study is underway to evaluate IO-108 in combination with atezolizumab and bevacizumab as a potential first-line therapy for hepatocellular carcinoma (HCC) (NCT04524871).