Monoclonal Antibody a ‘Novel Treatment’ for Mesothelioma?

A drug currently used to treat colorectal cancer and some types of head and neck cancer may also offer a new way to combat mesothelioma.

Malignant pleural mesothelioma is an asbestos-linked cancer that spreads across the mesothelial tissue surrounding the lungs. The disease is highly resistant to most conventional therapies and is often fatal within a year of diagnosis.  As the number of mesothelioma cases continues to increase in many developing counties, scientists around the world are studying mesothelioma cells for clues that could help them develop more effective treatments.

One clue is the overexpression of epidermal growth factor receptor (EGFR). EGFR is overexpressed by mesothelioma cells and several other types of cancer cells. The monoclonal antibody cetuximab, which is derived from human-mouse hybrid cells, targets EGFR and induces antibody-dependent cellular cytotoxicity (ADCC). Although cetuximab is used to treat some other types of cancer, it has not been well studied in mesothelioma.  Now, a team of Japanese researchers has released a study suggesting that cetuximab may by an alternative for mesothelioma patients who fail to respond to treatment.

To conduct the study, the researchers first measured the EGFR expression in mesothelioma cells in the lab, then exposed those cells to cetuximab and measured their growth.  They did the same in live mice that had been implanted with mesothelioma cells. In both cases, ADCC activity increased with even low doses of cetuximab. In a summary of their findings in The International Journal of Oncology, the researchers report, “In the mouse model, cetuximab treatment… significantly inhibited intrathoracic tumor growth and prolonged their survival”.

At the same time, researchers in Belgium are conducting a multicenter Phase II study of cetuximab as a first-line treatment for mesothelioma patients whose cancer has returned after radical surgery. In that study, cetuxmiab is being tested in combination with the chemotherapy drugs cisplatin, carboplatin and/or pemetrexed. The trial is ongoing and results should be reported in the future.

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