MGN1703 is a synthetic DNA-based TLR-9 agonist which has shown a good safety profile and a benefit compared to placebo in maintenance therapy of patients with metastatic colorectal carcinoma.In addition to the phase 1 and 2 trials with cancer patients a single dose crossover placebo-controlled phase 1 trial, MGN1703-C04, was performed to assess safety, pharmacokinetics (PK) and pharmacodynamics in healthy volunteers (HV).Standard PK parameters like mean Tmax (14h), AUC0-t (5001ngh/mL) and shape of the curve in the MGN1703-C04 trial were similar to single dose data obtained from cancer patients, with mean Tmax of 10h and AUC0-t of 5336ngh/mL. Notably, multiple doses resulted in similar levels without accumulation of MGN1703.In MGN1703-C04 elevated IP-10 levels were detected in the serum of HV peaking at 24–48h after dosing with MGN1703. The elevation of IP-10 is in keeping with data from cancer patients, which additionally showed activation of innate immune cells after dosing with MGN1703, e.g. up-regulation of CD169 on blood monocytes.The data show similarities between HV and cancer patients with respect to PK and – following-up downstream – the immunomodulatory profile, supporting the twice weekly application scheme of ongoing cancer studies. Further data will allow evaluation of possible association with clinical parameters.