Iressa (also known as gefitinib) was recently approved by the U.S. Food and Drug Administration for the treatment of a type of lung cancer called non-small-cell lung cancer. Unlike other anti-cancer drugs, Iressa is taken by mouth and is used alone, not in combination with other drugs for non-small-cell lung cancer. Unfortunately, Iressa has only been shown to cause shrinkage in the tumor; it has not been shown to cure the disease or to prolong lifespan. Iressa is being used in a number of research studies in combination with other anti-cancer drugs for a variety of forms of cancer.

About one out of every 100 patients who have received Iressa has developed a type of lung damage that is very difficult to treat. The damage is called pneumonitis and is caused by a reaction in the lungs to the drug itself. This only happens rarely, however, and seems to be related to previous treatment with chemotherapy or radiation. Although Iressa is new in the United States, it has been used in Japan for some time. About 23,000 people with lung cancer have been treated with Iressa. About one out of every 50 patients developed pneumonitis or pneumonia, and about one-third of those died as a result.

People taking Iressa should watch for cough, fever, and sudden difficulty breathing or worsening of breathing difficulties. These may be early signs of pneumonitis. Iressa can also cause diarrhea, nausea, rash and changes in liver function.