WASHINGTON, July 6 (Xinhua) -- The U.S. Food and Drug Administration (FDA) has approved Alimta (pemetrexed), the first drug available for maintenance therapy of advanced or metastatic lung cancer, the FDA said Monday in a statement.

    Patients with cancer often receive maintenance therapy to prevent the disease from progressing after their tumor has shrunk or the disease has stabilized in response to chemotherapy. Alimta disrupts metabolic processes that are dependent on the B-vitamin folate, a necessary ingredient for cell replication.

    There are two main types of lung cancers: small cell lung cancer and non-small cell lung cancer. Non-small cell lung cancer has several subtypes, including squamous cell, large cell, adenocarcinoma and mixed histology cancers.

    In a 600-patient clinical trial, people with predominantly squamous cell cancer did not benefit from Alimta. But those with other subtypes of non-small lung cancer survived an average 15.5 months following treatment compared with 10.3 months for patients who received an inactive substance (placebo). All patients in the study received standard medical care.

    "This drug represents a new approach in the treatment of advanced non-small cell lung cancer," said Richard Pazdur, director of Office of Oncology Drug Products in the FDA's Center for Drug Evaluation and Research. "This study demonstrates an advantage in overall survival in certain patients who received Alimta for maintenance therapy."

    Reported adverse events included damage to blood cells, fatigue, nausea, loss of appetite, tingling or numbness in the hands and feet, and skin rash.

    Alimta, manufactured by Eli Lilly & Co. of Indianapolis, initially was approved in 2004 for the treatment of patients with mesothelioma, a cancer frequently related to asbestos exposure.