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It is apparent that even the newest available chemotherapeutic regimens have not had a major impact in terms of improving survival for patients with metastatic (Stage IV) non-small cell lung cancer (NSCLC). This has prompted the search for different treatment strategies that may offer a significant survival advantage over the drugs that are currently available. Some of the novel treatment modalities that are currently being investigated for the treatment of non-small cell lung cancer include:

• Epidermal growth factor receptor inhibitors
• HER-2 inhibitors
• Angiogenesis inhibitors
• Protein kinase C inhibitors
• Farnesyl transferase inhibitors
• Exisulind (Aptosyn)

Epidermal Growth Factor Receptor Inhibitors

This is a new class of drugs that are designed to slow down or stop the growth of cancer cells by specifically inhibiting a key enzyme called tyrosine kinase that is thought to play an important role in the uncontrolled growth and proliferation of cancer cells. Examples of drugs in this class include:

• Gefitinib (Iressa)
• Erlotinib (Tarceva)
• Cetuximab (Erbitux)

HER-2 Inhibitors

HER-2 is a gene that plays an important role in the growth and repair of cells. The HER-2 gene directs the production of special proteins called HER-2 receptors. In some types of cancers, particularly breast cancer, the cells contain extra copies of the HER-2 gene which leads to overproduction of HER-2 receptor proteins. The discovery of the overproduction of HER-2 receptors in about 25% of breast cancer cases has led to a new targeted approach for treating breast cancer with specialized drugs called monoclonal antibodies. The monoclonal antibody trastuzumab (Herceptin) targets and blocks the function of the HER-2 cancer gene and is currently being used for the treatment of breast cancer patients who are HER-2 positive. In some patients with NSCLC, overproduction of the HER-2 receptor protein also occurs and these patients may be candidates for treatment with the monoclonal antibody trastuzumab (Herceptin). Clinical trials of trastuzumab for the treatment of HER-2 positive NSCLC are currently in progress.

Angiogenesis Inhibitors

It has long been recognized that tumor cells need a rich blood supply in order to continue to grow and spread. If the blood supply to a tumor is cut-off, the cells are robbed of the essential nutrients they require to grow and proliferate. Recently, drugs called angiogenesis inhibitors have been developed that specifically target and inhibit the growth of new blood vessels, thereby, cutting-off the blood supply to the tumor. One of the angiogenesis inhibitors that has received considerable attention in recent years for the treatment of lung cancer is bevacizumab (Avastin). Avastin, in combination with intravenous 5-fluorouracil-based chemotherapy, was previously approved for first or second-line treatment of patients with metastatic colon or rectal cancer.

Bevacizumab (Avastin) is a monoclonal antibody that targets a growth factor called VEGF that is thought to play an important role in new blood vessel formation (angiogenesis). In October 2006, the U.S. Food and Drug Administration (FDA) approved the use of bevacizumab (Avastin) in combination with carboplatin and paclitaxel for the initial systemic treatment of patients with unresectable, locally advanced, recurrent or metastatic, non-squamous, non-small lung cancer. Approval was based on an improvement in survival time in clinical trials involving 878 patients when Avastin was added to a standard chemotherapy regimen. The median survival time for patients treated with Avastin plus standard chemotherapy (carboplatin and paclitaxel) was 12.3 months as compared to 10.3 months for patients treated with standard chemotherapy alone.