Used primarily in chemotherapy, this compound is effective in treating colorectal cancer, especially in advanced or metastatic stages. It functions by inhibiting topoisomerase I, an enzyme critical for DNA replication, leading to DNA damage and cancer cell death. Often administered in combination with other agents like 5-fluorouracil and leucovorin (as part of the FOLFIRI regimen), it plays a key role in first- and second-line treatment protocols. It is also used in some cases of small cell lung cancer and pancreatic cancer. The drug is delivered intravenously and requires careful monitoring due to potential side effects such as severe diarrhea and neutropenia.