The purpose of the present study is to investigate the benefit of anti-cancer therapy administered on the basis of drug sensitivity testing. This concerns colorectal cancer patients who have previously received standard treatment.

Inclusion Criteria:

• Metastatic colorectal cancer

  • Biopsy proven adenocarcinoma compatible with colorectal origin (primary tumor or metastasis)
  • If only biopsy from metastasis can be obtained, the patient must have a previously resected or image proven tumor of the colon or rectum (scanning or endoscopy)
  • Non-resectable metastatic spread

• Previously exposed to or intolerance or contraindications to standard systemic therapy, defined as

  • oxaliplatin
  • irinotecan
  • 5-fluorouracil (or similar such as capecitabine, S1)
  • VEGF inhibitor bevacizumab
  • EGFR inhibitor panitumumab or cetuximab (if RAS/RAF wt)

• Progressive disease defined as progression according to RECIST 1.1

• ECOG performance status 0-2

• Age at least 18 years

• Adequate bone marrow, liver and renal function allowing systemic chemotherapy

  • Absolute neutrophil count ≥1.5x10^9/l and thrombocytes ≥ 100x10^9/l.
  • Bilirubin ≤ 1.5 x upper normal value and alanine aminotransferase ≤ 3 x upper normal value
  • Calculated or measured renal glomerular filtration rate at least 30 mL/min

• Anticonception for fertile women and for male patients with a fertile partner. Intrauterine device, vasectomy of a female subject's male partner or hormonal contraceptive are acceptable

• Written and orally informed consent

Exclusion Criteria:

• Incapacity, frailty, disability, or comorbidity to a degree that according to the investigator is not compatible with participation in the protocol
• Other active malignant disease requiring therapy
• Other systemic anti-cancer therapy (palliative radiotherapy is allowed).
• Pregnant (positive pregnancy test) or breast feeding women