['colorectal neoplasms', 'adenocarcinoma']
['metformin', 'irinotecan']

        Inclusion Criteria:

          -  18 years or older

          -  Biopsy-proven colorectal adenocarcinoma

          -  Ineligibility for curative intent therapy, e.g., surgery or radiation

          -  Disease progression after oxaliplatin (either adjuvant or palliative),
             fluoropyrimidine (either adjuvant or palliative), irinotecan, and if Kras wild type a
             anti-EGFR therapy

          -  Assessable disease according to RECIST v1.1

        Exclusion Criteria:

          -  known hypersensitivity to metformin or irinotecan

          -  Uncontrolled Central nervous system metastasis

          -  Acute or chronic severe infection
      