title: Molecular Pathways: Clinical Applications and Future Direction of Insulin-like Growth Factor-1 Receptor Pathway Blockade.
abstract: The IGF1R signaling pathway is a complex and tightly regulated network that is critical for cell proliferation, growth, and survival. IGF1R is a potential therapeutic target for patients with many different malignancies. This brief review summarizes the results of clinical trials targeting the IGF1R pathway in patients with breast cancer, sarcoma, and non-small cell lung cancer (NSCLC). Therapeutic agents discussed include both monoclonal antibodies to IGF1R (dalotuzumab, figitumumab, cixutumumab, ganitumab, R1507, AVE1642) and newer IGF1R pathway targeting strategies, including monoclonal antibodies to IGF1 and IGF2 (MEDI-573 and BI 836845) and a small-molecule tyrosine kinase inhibitor of IGF1R (linsitinib). The pullback of trials in patients with breast cancer and NSCLC based on several large negative trials is noted and contrasted with the sustained success of IGF1R inhibitor monotherapy in a subset of patients with sarcoma. Several different biomarkers have been examined in these trials with varying levels of success, including tumor expression of IGF1R and its pathway components, serum IGF ligand levels, alternate pathway activation, and specific molecular signatures of IGF1R pathway dependence. However, there remains a critical need to define predictive biomarkers in order to identify patients who may benefit from IGF1R-directed therapies. Ongoing research focuses on uncovering such biomarkers and elucidating mechanisms of resistance, as this therapeutic target is currently being analyzed from the bedside to bench.
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Wade T
authors.initials: WT
authors.lastname: Iams
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee. Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee. Vanderbilt-Ingram Cancer Center, Nashville, Tennessee. christine.lovly@vanderbilt.edu.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lovly
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008297:Male; D058990:Molecular Targeted Therapy; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D017526:Receptor, IGF Type 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D057170:Translational Research, Biomedical; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D017526:Receptor, IGF Type 1