A phase II clinical trial of ZD1839 (gefitinib) in combination with docetaxel as first-line treatment in patients with advanced breast cancer

Abstract

1059 Background: We conducted a phase II multi-institutional trial of gefitinib and docetaxel as first-line treatment in patients with metastatic breast cancer. The primary objectives were to determine the clinical benefit rate (defined as the proportion of patients who experienced confirmed complete response or partial response or who had stable disease for at least 24 weeks) and the toxicity profile of the combination treatment. Methods: All patients had histologically confirmed breast cancer with metastatic disease. They may have received adjuvant chemotherapy, but no prior docetaxel or prior chemotherapy for metastatic disease. Patients received gefitinib 250 mg once daily and docetaxel 75 mg/m2 every 3 weeks, until tumor progression, toxicity or other reasons for discontinuation. Results: Between April 2003 and September 2004, 33 patients were enrolled at 11 participating institutions. Patients received a median of 5 cycles of treatment. The clinical benefit rate was 51.5% (95% CI: 33.5% - 69.2%). There was 1 confirmed complete response and 12 confirmed partial responses, and the overall objective response rate was 39.4% (95% CI: 22.9% - 57.9%). Four patients had stable disease for = 24 weeks. The median duration of clinical benefit was 10.9 months (95% CI: 6.0 - 17.6 months). The most common reason for study discontinuation was disease progression (16 patients), followed by toxicity (10 patients). Toxicities were mainly attributable to docetaxel, including = grade 3 neutropenia in 43% of patients. Conclusion: The combination of gefitinib and docetaxel is an active regimen in patients with previously untreated metastatic breast cancer. Further work is needed to determine which subset of patients with breast cancer will benefit from gefitinib. No significant financial relationships to disclose.