ODN 1826 sodium is a class B CpG ODN (oligodeoxynucleotide) and a TLR9 agonist. It induces the production of NO and iNOS and enhances apoptosis. ODN 1826 sodium boosts immune surveillance and increases the size of atherosclerotic plaques. It exhibits antitumor activity against lung cancer, glioma, and melanoma.

ODN 1826 (1 μg/mL; 24 h) sodium stimulates the production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in RAW 264.7 mouse macrophages.

CpG-1826 (100 μg/tumor; intratumoral injection; up to 4 times every 3 days) sodium can slow the growth of subcutaneously implanted GL261 gliomas in C57BL/6NTac mice by enhancing the infiltration of macrophages and B cells into the tumor, significantly delaying growth in about 50% of the mice. In a model of chronic vascular injury, ODN 1826 (18 nM; subcutaneous injection; thrice weekly for a total of 7 weeks) sodium increases atherosclerotic plaque size in mice. Additionally, ODN 1826 (0.05 mg; intraperitoneal injection; on days 1, 3, 5, 8, 11, 13) sodium exhibits potent anti-tumor growth activity in a Lewis lung carcinoma mouse tumor model.