MK-0646 Insulin Growth Factor 1 Receptor Antibody in Stage IIIb or IV Metastatic Non-Squamous Lung Cancer

Insulin-like Growth factor 1 receptor (IGF-1R) is a tyrosine kinase receptor that regulates cell growth, proliferation and apoptosis.(4) Increased IGF1 signaling results in upregulation of proliferation and inhibition of apoptosis through RAF and PI3K pathways.(5) Several types of cancer, including non-small cell lung cancer, express IGF-1R and its ligand. The sequestration of IGF by IGF binding protein was associated with improved survival in patients with resected stage I lung cancer.(6) High expression of IGF-1R is associated with poor survival in surgically resected stage I lung cancer, specifically adenocarcinoma subtype. Patients with adenocarcinoma and never smoker had higher expression of IGF-1R vs. squamous cell carcinoma and smokers.(7). Low IGF-1R expression was associated with significant improvement in survival in the adenocarcinoma lung cancer but there was a lack of correlation between expression of IGF1R and survival in patients with squamous cell histology. Monoclonal antibodies target the extracellular domain of IGF-IR and small molecules inhibit IGF-1R kinase. This is a potential new strategy in the treatment of lung cancer.