This is a Phase 1/2, proof-of-principle clinical study to assess safety and efficacy of a intradermally administered tumor vaccine (MGN1601). The study will be conducted in patients with advanced renal cell carcinoma.

Twenty four patients with advanced RCC will be included in this open, single-arm study.

The treatment will last 12 weeks. The investigational product (MGN1601) will be administered intradermally for a total of 8 applications, whereas the first 3 applications will be administered weekly, and the following 5 applications will be administered bi-weekly.

Patients who will develop disease control (CR, PR, or SD) by week 12 will be proposed to participate in the extension phase of the study. The extension phase will be continued until disease progression in each patient, however, maximally up to week 120 (total treatment duration 2.5 years). During this time period the investigational product will be administered 5 times by weeks 24, 36, 48, 72, and 120.

Inclusion Criteria:

• Male and female subjects older than 18 years of age
• Histologically confirmed renal cell carcinoma
• Radiologically confirmed advanced disease defined as unresectable locally reccurrent or metastatic disease (AJCC Stage IV)
• Previous nephrectomy
• No standard therapy is available for the patient
• At least 4 weeks after previous radiotherapy prior to study treatment
• At least 1 week after previous systemic therapy prior to study treatment
• At least one lesion measurable by modified RECIST criteria
• ECOG performance status 0-1
• Adequate organ function including hematopoietic organs
• MSKCC prognostic ctiteria < 3 predictors of short survival
• Negative urine pregnancy test in women with childbearing potential
• Women of childbearing potential and all male participants are willing to use acceptable methods of contraception (birth control pills, barriers)
• Expected adequacy of follow-up
• Signed informed consent form (ICF).

Exclusion Criteria:

• Clinically significant concomitant diseases or conditions unrelated to the underlying malignancy or therapy, which in opinion of the investigator would lead to an unacceptable risk for the subject to participate in the study
• Known hypersensitivity to any component of the study drug
• Prior or current other malignancy, except adequately treated superficial bladder cancer, basal or squamous cell carcinoma of the skin or other cancer for which the subject has been disease free for more than 3 years
• Active brain metastases except adequately treated brain metastases with no progression for at least 3 months
• Active or uncontrolled infections
• Transfusion-dependent anemia
• History of autoimmune disease or immune deficiency
• Concurrent chronic systemic immune therapy, corticosteroids or other immunosuppressant medication
• Concurrent radiotherapy within the last 4 weeks prior to study treatment and/or during the course of the study
• Concurrent immunotherapy or targeted therapy within the last 1 week prior to study treatment and/or during the course of the study
• HIV seropositivity or active hepatitis B or C infection
• Planned major surgery during the study
• Participation in other clinical studies during this clinical study
• Vaccination within 3 months prior to the first treatment day
• Any medical, mental, psychological or psychiatric condition which in opinion of the investigator would not permit the subject to complete the study or understand the patient information
• Pregnancy and/or nursing
• Presence of drug and/or alcohol abuse
• Commitment to an institution by virtue of an order issued either by judicial or administrative authorities.