By Ronald Natale‚ MD
Medical Director‚ Cedars-Sinai Comprehensive Cancer Center
Los Angeles

Question:
I have been reading a lot about Iressa. What is the current status of this drug for patients with lung cancer?

Answer:
Iressa™ (gefitinib)‚ the first in a new class of anticancer drugs known as selective epidermal growth factor receptor (EGFR) inhibitors‚ is currently under consideration for approval by the U.S. Food and Drug Administration (FDA) for patients with advanced non—small-cell lung cancer (NSCLC) who have progressed after at least two prior chemotherapy treatment regimens. Iressa was approved for use in Japan last summer. This is promising news for patients with NSCLC‚ the leading cause of cancer deaths in the United States.
Administered as a once-daily oral tablet‚ Iressa acts within the cell to target and block growth signals involved in the growth and survival of the tumor. This targeted mode of action is different from traditional chemotherapy and has fewer side effects.

The FDA filing for accelerated approval of Iressa is based on data from two phase II trials‚ which studied the drug in patients with locally advanced or metastatic NSCLC who had relapsed after one or two chemotherapy treatments. Approximately 10-20% of patients in the trials experienced tumor shrinkage of at least 50% in size. Many patients also experienced an improvement in their disease-related symptoms.

Side effects of Iressa include diarrhea and an acne-like skin rash. In Japan‚ it has been reported that Iressa has been associated with a 1-2% incidence of interstitial lung disease (ILD)‚ an inflammation and scarring of the tissue between the air sacs in the lung. ILD is a known complication of many lung diseases‚ including advanced lung cancer. Changes in the lung are common findings in persons with advanced lung cancer who receive radiation therapy and chemotherapy as part of their standard care. ILD has been widely observed in clinical trials with both chemotherapy and radiation therapy. Patients and physicians should be informed of the potential risk and watch for signs and symptoms‚ which in most cases will be due to progressive lung cancer.

On Sept. 24‚ 2002‚ the Oncologic Drugs Advisory Committee made a clear recommendation to the FDA supporting the approval of Iressa. On Jan. 9‚ 2003‚ the FDA announced it required more time to review the information submitted for approval of Iressa. An FDA decision is now expected by May 5‚ 2003.

At the urging of patients and physicians‚ and with the support of the FDA‚ AstraZeneca‚ the drug’s creator and manufacturer‚ established an Expanded Access Program in fall 2000 to provide Iressa to patients with advanced NSCLC who have exhausted other treatment options. In the past two years‚ nearly 20‚000 patients in the United States have received Iressa through this program.

In addition to lung cancer‚ EGFR receptors are found in a variety of common solid tumors‚ including NSCLC‚ colorectal cancer‚ head and neck cancer‚ breast cancer‚ and gastric cancer. Clinical studies are under way to determine if Iressa will be of benefit in these tumor types as well.

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