A Randomized, Multicenter, Open-label Clinical Study to Compare the Efficacy of Intravenous to Oral Iron on Anemia Treatment

INTERVENTION: Drug : Experimental: Intravenous iron group Single‐dose intravenous infusion of 1000mg iron isomaltoside (MonoFer®) baseline, after 6 weeks, and 12 weeks. total 3 times. Active Comparator: Oral iron group Oral therapy with 100 mg oral ferrous sulfate twice daily CONDITION: Neoplasms PRIMARY OUTCOME: blood results(Hb, iron, TSAT, TIBC, sTFR, hepcidin, rediculocyte) SECONDARY OUTCOME: changes in microbiome metabolomics Quality of life assessed by EORTC QLQ‐C10 The change of anemia‐related laboratory results The change of hemoglobin Treatment‐related adverse events graded according to NCI CTCAE version 5.0. INCLUSION CRITERIA: ‐ Adults over 19 years of age ‐ Subjects were diagnosed with metastatic colorectal cancer before participating in the study and were scheduled for chemotherapy or were currently undergoing chemotherapy with first (1st line) or second (2nd line) treatment drugs ‐ Subjects whose hemoglobin level is within the range of 8.0‐11 g/dL, or who have experienced a decrease in hemoglobin of 2 g/dL or more during chemotherapy ‐ Ability to write/submit an informed consent form before participating in study