An expert panel of the American Society of Clinical Oncology (ASCO) has updated their Clinical Practice Guidelines for the treatment of non-small-cell lung cancer. For the first time the panel has recommended AstraZeneca's Iressa (gefitinib) for the treatment of patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC) after failure of both platinum based and docetaxel chemotherapies. The new guidelines were recently provided to the society's membership and published in the Journal of Clinical Oncology. Iressa is the first treatment for NSCLC other than surgery, radiation or chemotherapy to be included in the ASCO guidelines.
Lung cancer is the leading cause of cancer deaths in the United States, estimated to account for approximately 157,000 deaths in 2003. NSCLC is the most common form of lung cancer, accounting for 80 per cent of all lung cancer cases. The ASCO guidelines also state that while the FDA indication allows Iressa to be used for any patient with NSCLC intolerant or resistant to both platinum-based and docetaxel chemotherapy, preliminary data suggest that the population best suited for treatment with Iressa remains to be defined, and that similar to other chemotherapies used as salvage therapy, benefits may only be seen in a small percentage of patients.
The US Food and Drug Administration (FDA) approved Iressa in May 2003 based upon data from a US Phase II trial that studied two doses of Iressa in a total of 216 patients who received both platinum-based and docetaxel chemotherapies. Included in the FDA analysis were 142 of the 216 patients. In the group receiving the recommended dose of 250 mg/day, 13.6per cent (95per cent CI: 6.4-24.3) of the patients had their tumor shrink by at least 50per cent. Higher doses did not give a better response and more side effects were observed. The overall response rate for both doses combined in all 142 patients was 10.6per cent (95per cent CI: 6.0-16.8). Median duration of response was 7 months (range 4.4 to 18.6+ months). The response rates appeared to be highly variable in subgroups of the treated population (gender, smoking history and histology) varying from 4.6-29.4per cent.