The US Food and Drug Administration (FDA) has approved a new drug for treatment of malignant mesothelioma, a cancer of the lining of the chest and abdomen. Pemetrexed disodium, sold under the name Alimta, is the first drug shown to help patients with this rare form of cancer.

"Up to now, there has been no effective treatment for mesothelioma," said FDA Commissioner Mark McClellan in announcing the approval. "Alimta offers new promise in treating this fatal cancer."

Malignant mesothelioma is a cancer associated with heavy exposure to asbestos that affects 2,000 to 3,000 Americans every year. Because symptoms (including lower back pain and shortness of breath) are often mistaken for problems related to other conditions, mesothelioma is frequently diagnosed at an advanced stage, when it is very difficult to treat with surgery or radiation. Patients in this situation usually survive a year or less.

Alimta was approved after a clinical trial of 448 patients showed it increased survival time by about 30%. Patients who received Alimta and the standard chemotherapy drug cisplatin lived an average of about 12 months, compared to about 9 months for patients treated with cisplatin alone. Patients on Alimta also showed improved lung function.

Mesothelioma patients who are not candidates for surgery or whose cancer cannot be removed surgically may be treated with Alimta, said manufacturer Eli Lilly. The drug is given in a single 10-minute infusion every 3 weeks.

Possible side effects include low white blood cell count, nausea, vomiting, fatigue, rash, and diarrhea. Patients must take daily doses of folic acid and vitamin B12 to reduce the severity of side effects.