Inclusion Criteria:

Phase I part inclusion criteria (inclusion criteria for phase IIa part will be defined
later using a study amendment):

- Histologically confirmed, surgically resected colorectal cancer of advanced stage
(UICC stage III/UICC stage IV). This comprises patients with lymph node metastases
(UICC stage III), metastasis to one distant organ (UICC IV, M1a), to more than one
distant organ, or patients with peritoneal carcinosis (UICC IV, M1b)

- Detection of high level microsatellite instability (MSI-H) in the resected tumor
sample according to the international consensus criteria (multiplex PCR of
quasi-monomorphic microsatellite markers BAT25, BAT26, CAT25), see Appendix 1.

- Prior adjuvant standard therapy (chemotherapy with 5-fluorouracil/folinic acid,
oxaliplatin, irinotecan or combinations of these) OR Prior palliative standard
therapy in the first, second and third line (chemotherapy with 5-fluorouracil,
oxaliplatin, irinotecan or combinations of these and/or treatment with anti-EGFR
antibodies cetuximab or panitumumab alone or in combination with chemotherapy) with
either complete or partial remission, stable disease, or disease progression under
therapy; OR Patient has refused adjuvant or palliative standard therapy (chemotherapy
using 5-fluorouracil, oxaliplatin, or regimens combining these).

- Expected survival of at least six months.

- Full recovery from surgery or radiation therapy

- ECOG performance status 0, 1 or 2.

- The following laboratory results:

- Neutrophil count ≥ 1.5 x 109/L

- Lymphocyte count ≥ 0.5 x 109/L

- Platelet count ≥ 100 x 109/L

- Serum bilirubin < 2mg/dL

- Male or female patients ≥ 18 years old

- Last therapy discontinued at least 4 weeks prior to vaccination.

- Patient´s written informed consent for participation in the trial

Exclusion Criteria:

- Prior treatment with FSPs AIM2(-1), HT001(-1) and TAF1B(-1)

- Clinically significant heart disease (NYHA Class IV).

- Other serious illnesses, eg, serious infections requiring antibiotics or bleeding
disorders.

- History of immunodeficiency disease or autoimmune disease.

- Metastatic disease to the central nervous system for which other therapeutic options,
including radiotherapy, may be available.

- HBV, HCV or HIV positivity.

- Chemotherapy, any type of radiation therapy, or immunotherapy within 4 weeks before
study entry

- Concomitant treatment with steroids, antihistaminic drugs, or nonsteroidal
anti-inflammatory drugs (unless used in low doses for prevention of an acute
cardiovascular event or for pain control). Topical or inhalational steroids are
permitted.

- Participation in any other clinical trial

- Pregnancy or lactation.

- Women of childbearing potential who are not using a medically acceptable means of
contraception.

- Psychiatric or addictive disorders that may compromise the ability to give informed
consent.

- Lack of availability of a patient for immunological and clinical follow-up
assessment.

- Brain metastases (symptomatic and non-symptomatic)