A multicentre phase II study on gefitinib in taxane- and anthracycline-pretreated metastatic breast cancer.

Epidermal growth factor receptor (EGFR) is considered to be a viable drug target in a variety of solid tumors. The clinical benefit and safety of the EGFR tyrosine kinase inhibitor gefitinib ('Iressa')1 was evaluated in this Phase II, multicentre study of patients with taxane and anthracycline pretreated, metastatic breast cancer. Gefitinib (500 mg/day) was given to 58 patients until disease progression. Primary endpoint was the clinical response rate to the study treatment. One patient (1.7%) had objective partial tumor response of her liver and pleural metastasis. Fifty-seven patients (98.3%) were non-responders with 52 patients (89.7%) having progressive disease and five patients (8.6%) were not evaluable. Two patients reported a significant improvement in pain at metastatic sites (1 liver, 1 bone). The median time to progression was 61 days (95% CI : 54-82 days) and the proportion of patients alive and progression free at 6 months at trial closure was 1.8% (95% CI : 0.0-5.2%). The median survival time was 357 days (95% CI : 257-441 days). Fifty-four patients (93.1%) discontinued study medication prematurely due to disease progression and three (5.2%) due to adverse events (diarrhea, pruritus, peripheral edema). Gefitinib monotherapy at 500 mg daily did not appear to be efficacious in the treatment of heavily pretreated metastatic breast cancer patients. It was well tolerated and the side effect profile was as expected from current knowledge of the drug. There was no correlation between EGFR expression and response in this study.