New Drug for Pleural Mesothelioma

In this study, people with pleural mesothelioma (cancer of the lining of the lung) lived longer and had less pain and shortness of breath if they received the new chemotherapy drug pemetrexed. The phase III randomized study is the largest meso-thelioma trial ever conducted, involving 456 patients. Patients were chosen at random to receive pemetrexed plus cisplatin (a common chemotherapy drug) or cisplatin alone.

Mesothelioma patients treated with pemetrexed plus cisplatin lived about a year after their diagnosis, nearly three months longer than patients who received only cisplatin.

The two-drug combination caused the cancer to shrink in 41% of patients, compared to 17% of patients who received only cisplatin. The drug combination was also more effective at reducing pain and shortness of breath, symptoms commonly experienced by mesothelioma patients.

Shortly after the study began, many patients began having low levels of folic acid and vitamin B12. These patients who re-ceived pemetrexed were more likely to experience severe side effects (very low white blood cell counts, severe diarrhea, and severe mouth ulcers) than patients who received only cisplatin.

Following the observation, all patients in the study began receiving folic acid and vitamin B12. This reduced the side effects associated with pemetrexed, and more patients benefited from the drug.

Mesothelioma is most commonly caused by exposure to asbestos. Peme-trexed is a cousin of an early chemotherapy drug, methotrexate, used to treat other types of cancer. Methotrexate blocks one enzyme necessary for cell division and tumor growth, and pemetrexed blocks three such enzymes. (Abstract #5)

What does this mean for patients?

Pemetrexed is the first drug shown to prolong the lives of people with mesothelioma. "The results are very encouraging and significant because mesothelioma patients and their families now have proof that this new chemotherapy drug offers real and tangible benefits," said Nicholas J. Vogel-zang, MD. Dr. Vogelzang is the Fred C. Buffett Professor and Director of the University of Chicago Cancer Research Center.