K3-SPG

**K3-SPG** is an investigational nanoparticulate immunostimulatory complex comprising the humanized K-type CpG oligodeoxynucleotide K3 and schizophyllan, a beta-1,3-glucan derived from the mushroom *Schizophyllum commune*. Schizophyllan wraps the CpG oligonucleotide to form a soluble nanoparticle that acts primarily as a Toll-like receptor 9 agonist. K3-SPG promotes innate immune activation, including type I interferon, type II interferon, interleukin-12, and cytotoxic T-cell responses, and has been studied as a vaccine adjuvant and as an in situ cancer immunotherapy. Preclinical studies have reported antitumor activity following intravenous and intratumoral administration, including in pancreatic ductal adenocarcinoma, colorectal cancer, pancreatic cancer peritoneal dissemination, and esophageal squamous cell carcinoma models. The platform originated from work at the National Institutes of Biomedical Innovation, Health and Nutrition and has been subject to joint patenting with Daiichi Sankyo.