Targeted therapy using novel agents in the treatment of non-small-cell lung cancer.

Patients with advanced non-small-cell lung cancer (NSCLC) have a poor prognosis and high mortality. The therapeutic improvement caused by the new generation of cytotoxic agents seems to have reached a plateau. The main categories of targeted therapeutics applicable for NSCLC include receptor-targeted therapy, signal transduction or cell-cycle inhibition, angiogenesis inhibitors, gene therapy, and vaccines. Several major classes of agents directed at specific cellular mechanisms exist for the treatment of NSCLC. The anti-epidermal growth factor receptor (EGFR) group contains trastuzumab and IMC-C225, monoclonal antibodies against EGFRs that are overexpressed in many cancers. OSI-774 and ZD1839 are inhibitors of EGFR tyrosine kinase, a key enzyme of the signaling pathway. Farnesyl transferase inhibitors, such as SCH66336, and protein kinase C inhibitors, such as ISIS 3521, have also shown antitumor activity. Antiangiogenesis agents that have shown promise include TNP-470, recombinant endostatin, and angiostatin. Antibodies to vascular endothelial growth factor (VEGF) also seem to control tumor progression and may prolong survival. LY317615, an inhibitor of protein kinase Cb, augmented the tumor growth delay produced by cytotoxic drugs. All of these agents are in different phases of clinical testing and have shown encouraging activity as single agents or in combination with chemotherapy drugs. These new agents are more target specific, less toxic, easier to administer, and may lead to enhanced safety and survival for patients with advanced NSCLC.