This clinical trial is focused on studying the effects of intravenous iron treatment in patients with colorectal cancer who have iron deficiency but are not anemic. The treatment being tested is called Monofer, which contains the active substance ferric derisomaltose. This study will compare the effects of Monofer with a placebo to understand how it impacts physical capacity and immune function in these patients.
The purpose of the study is to evaluate how the iron treatment affects the patients’ physical abilities and immune system, particularly looking at changes in the Neutrophil to Lymphocyte Ratio (NLR) and using a method called Nanostring to analyze immune responses. The study will also investigate the effects of the treatment on the tumor environment and the patients’ overall health outcomes, both in the short and long term.
Participants in the study will receive the treatment through an intravenous infusion, which means the solution is given directly into a vein. The study will monitor various health indicators, including physical capacity, immune function, and any side effects. The goal is to gather information that could help improve treatment strategies for patients with colorectal cancer who have iron deficiency.



Denmark