AbstractBackgroundImmune therapies are currently under intensive investigation providing in many cases excellent responses in different tumors. Other possible approach for immunotherapy is a targeted intratumoral delivery of interleukin 12 (IL-12), a cytokine with anti-tumor effectiveness. Due to its immunomodulatory action, it can be used as an imunostimulating component to in situ vaccinating effect of local ablative therapies. We have developed a phIL12 plasmid devoid of antibiotic resistance marker with a transgene for human IL-12 p70 protein. The plasmid can be delivered intratumorally by gene electrotransfer (GET).Patients and methodsHere we present a first-in-human clinical trial protocol for phIL12 GET (ISRCTN15479959, ClinicalTrials NCT05077033). The study is aimed at evaluating the safety and tolerability of phIL12 GET in treatment of basal cell carcinomas in patients with operable tumors in the head and neck region. The study is designed as an exploratory, dose escalating study with the aim to determine the safety and tolerability of the treatment and to identify the dose of plasmid phIL12 that is safe and elicits its biological activity.ConclusionsThe results of this trail protocol will therefore provide the basis for the use of phIL12 GET as an adjuvant treatment to local ablative therapies, to potentially increase their local and elicit a systemic response.