Preliminary safety results of an ongoing phase I/II clinical study of MGN1601, a tumor vaccine comprising allogeneic, gene-modified, and irradiated tumor cells in combination with an immunomodulator in patients with metastatic renal cell carcinoma (ASET study)

392 Background: MGN1601 is a cell-based RCC tumor vaccine MGN1601 consisting of two active pharmaceutical ingredients: genetically modified allogeneic (human) cells transfected with four different MIDGE vectors encoding IL-7, GM-CSF, CD80 and CD154 and a synthetic DNA-based immunomodulator dSLIM-30L1, a TLR-9 agonist. The vaccine is being developed for treatment of patients with advanced RCC. Its prophylactic and therapeutic anti-tumor activity has been shown in several in-vivo models. A good safety profile of MGN1601 was shown in a wide program of acute and chronic toxicity studies. Based on these promising data, this phase 1/2 study was started in patients with advanced RCC. Methods: This multicentric open clinical study for the assessment of safety and efficacy of MGN1601 in patients with advanced RCC was initiated in October 2010. A total of 24 patients have to be recruited into the study. The treatment consists of 8 MGN1601 treatments administered as follows: the first 3 treatments are administered on a weekly basis, and the consecutive 5 treatments on a bi-weekly basis. The treatment dose contains 107 transfected tumor cells and 5 mg dSLIM per administration, which has been proven to be safe with a high safety margin in repeated toxicity studies. The efficacy and safety of the study treatment will be evaluated based on extensive immunological tests, radiological assessment, safety laboratory results and assessments of the quality of life. Here, the first safety data are presented. [Table: see text]