The FDA has approved Gleevec (imatinib mesylate) for a new indication – keeping cancer from growing in patients following surgical removal of a gastrointestinal stromal tumor or GIST. GIST is a fairly rare form of cancer that originates in cells found in the wall of the GI tract. These cells, known as interstitial cells of Cajal, are part of the autonomic nervous system, which helps to control the movement of food and liquid through the stomach and intestines. Gleevec, first approved by the FDA in 2001, is one of the first drugs in a class of agents that block cellular communications that result in tumor growth”Approval of Gleevec offers health care professionals and patients an important new therapeutic option for patients with this uncommon gastrointestinal disease,” said Richard Pazdur, M.D., director, Office of Oncology Drug Products, Center for Drug Evaluation and Research, FDA. “It illustrates how the continued study of a once novel drug throughout its product lifecycle can yield new and important uses.” About 5,000 to 6,000 new patients are diagnosed with GIST each year in the United States. Because symptoms of GIST are no different than other GI complaints such as nausea and vomiting, the cancer is difficult to detect early. Patients initially undergo surgery to remove the tumor but GIST commonly recurs. Gleevec is intended to be given to patients following surgery to help prevent tumor recurrence. The efficacy of Gleevec was established in a clinical trial in which patients received either Gleevec or a placebo for one year after surgical removal of the tumor. The optimal treatment duration is not known. There were significantly fewer recurrences of GIST in patients receiving Gleevec than in patients who did not. The most frequently reported adverse reactions were diarrhea, fatigue, nausea, swelling of the feet, decreased red blood cell counts, rash, vomiting and abdominal pain. Gleevec is manufactured by Novartis AG, Basel, Switzerland.
