SD-101 + ipilimumab + nivolumab

**SD-101 + ipilimumab + nivolumab** is a combination therapy comprised of SD-101, a synthetic CpG oligonucleotide Toll-like receptor 9 (TLR9) agonist, with two immune checkpoint inhibitors: ipilimumab (a CTLA-4-blocking monoclonal antibody) and nivolumab (a PD-1-blocking monoclonal antibody). SD-101 is administered intratumorally to activate plasmacytoid dendritic cells, inducing local and systemic immune activation primarily via type I interferon release and dendritic cell maturation. Ipilimumab and nivolumab, given intravenously, act systemically to relieve immune inhibition and further enhance T cell-mediated antitumor responses. This immuno-oncology regimen is being explored in solid tumors such as metastatic melanoma and other advanced cancers, aiming to increase the proportion of patients responding to immunotherapy, particularly those with low immune infiltrates or resistance to checkpoint blockade.