Irinotecan is a chemotherapy drug classified as a topoisomerase I inhibitor, used primarily in the treatment of colorectal cancer and other solid tumors. It was first synthesized in Japan in the late 1980s and introduced clinically in the 1990s. Irinotecan is a semi-synthetic derivative of camptothecin, a natural alkaloid extracted from the Chinese tree Camptotheca acuminata. The drug works by interfering with DNA replication in cancer cells, ultimately causing cell death. Over time, irinotecan became an important component of combination chemotherapy regimens, such as FOLFIRI, to improve treatment outcomes in metastatic colorectal cancer. Its development marked a significant advancement in targeted cancer therapy, offering a novel mechanism distinct from traditional cytotoxic agents.
