Intravenous Ferric Carboxymaltose vs. Oral Iron Substitution in Patients With Metastatic Colorectal Cancer (CRC) and Iron Deficiency Anemia: a Randomized Multicenter Treatment Optimization Study.

• FerInject (Drug): FerInject: max. 2.000 mg of ferric carboxymaltose over max. 2 weeks (max. 1.000 mg per week).
• Ferro sanol (Drug): 200 mg ferro sanol per day over 12 weeks

Primary outcomes

• Rise or normalization of hemoglobin [12 weeks]

Secondary outcomes

• Fatigue as measured by EORTC-QLQ-FA13 [12 weeks]
• Quality of life as measured by EORTC-C30 [12 weeks]
• Handgrip strength as measured by Hydraulic Hand Dynamometer [12 weeks]
• Number of allogenic blood transfusions (in total and per patient) [12 weeks]
• Time until rise or normalisation of hemoglobin [12 weeks]
• Genesis of the iron deficiency anemia [12 weeks]
• Number of therapy with recombinant erythropoietin [12 weeks]
• Dose of therapy with recombinant erythropoietin [12 weeks]
• Duration of therapy with recombinant erythropoietin [12 weeks]
• Inflammatory parameters [12 weeks]
• Influence nutritional status on iron deficiency anemia as measured by Nutritional Risk Screening (NRS 2002) [12 weeks]
• Influence nutritional status on therapy success as measured by Nutritional Risk Screening (NRS 2002) [12 weeks]
• Tolerance [12 weeks]
• Incidence and severity of adverse events [12 weeks]: incidence and severity of adverse events according to CTCAE (Common Terminology Criteria for Adverse Events) Version 4 criteria as assessed at day 1, 8, 15, 36, 50 and 64 and at end of treatment.
• Dropout rate due to toxicity or patient will [12 weeks]
• Overall survival [12 weeks]

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Metastatic or inoperable colorectal carcinoma. No curative therapy available.
2. Current palliative chemotherapy. Patients under conversion therapy must not be enrolled to this study.
3. Iron deficiency anemia: hemoglobin ≤ 10.5 g/dl and transferrin saturation < 20 % and/or serum ferritin < 20 ng/ml
4. Male and female patients aged ≥ 18 years; maturity
5. ECOG ≤ 2
6. Written informed consent
7. Life expectancy > 6 months
8. Body weight ≥ 40 kg

Exclusion Criteria:

1. Oral or intravenous iron substitution within the last 4 weeks
2. Age < 18 years or body weight < 40 kg
3. Absorption dysfunction due to short bowel syndrome or after gastric resection
4. Therapy with recombinant erythropoietin within the last 4 weeks
5. Chronic diarrhea
6. Chronic inflammatory bowel disease
7. Ferritin > 800 mg/dl at baseline
8. Hypersensitivity or contraindication to ferric carboxymaltose or iron (II) glycine sulphate complex
9. Known vitamin B12 or folic acid anemia
10. Necessary total parenteral nutrition
11. Participation in another interventional study
12. Pregnancy or lactation