dalotuzumab + irinotecan

Dalotuzumab + irinotecan is an investigational combination therapy evaluated primarily for metastatic colorectal and rectal cancer. Dalotuzumab is a humanized IgG1 monoclonal antibody targeting the insulin-like growth factor 1 receptor (IGF-1R), which plays a role in cancer cell proliferation, survival, and resistance to therapy. By binding IGF-1R, dalotuzumab blocks activation by its ligands (IGF-1 and IGF-2), inhibiting downstream signaling pathways such as PI3K/Akt/mTOR, inducing apoptosis, and potentially mediating antibody-dependent cellular cytotoxicity. Irinotecan is a small molecule chemotherapeutic agent that inhibits topoisomerase I, leading to DNA damage and cell death in rapidly dividing cells. The combination has been studied in phase II clinical trials for patients with metastatic KRAS wild-type colorectal or rectal cancers—often compared against standard regimens like cetuximab plus irinotecan. The rationale was that dual inhibition of IGF-1R (dalotuzumab) and DNA replication (irinotecan) might overcome resistance mechanisms seen with EGFR inhibitors alone. However, clinical studies did not demonstrate improved survival outcomes over standard therapies[1][2][7].