Comparing Anastrozole-Placebo to the Combination Anastrozole-ZD1839 in Postmenopausal Patients With Estrogen Receptor and/or Progesterone Receptor Metastatic Breast Cancer

This is a phase II, multicenter, double-blind, randomized, placebo-controlled trial. Patients will be randomized in a double-blind manner in a 1:1 ratio to receive either 250 mg/day ZD1839 or matched placebo in combination with 1 mg/day anastrozole. The dose of ZD1839 has been selected based on clinical studies in other tumor types suggesting identical efficacy together with a better toxicity profile in patients treated at 250 mg compared to 500 mg/day. The 1 mg dose of anastrozole is the standard approved dose.

Inclusion criteria

• Female postmenopausal patients aged 18 years or older with newly diagnosed metastatic breast cancer.
• Patients with recurrent disease during or after adjuvant tamoxifen or patients who are hormone therapy naïve are eligible for this trial.
• A paraffin embedded tumor tissue block or slides from either the metastatic or primary tumor site is required.

Exclusion criteria

• Patients cannot be on hormone replacement therapy while on study.
• Prior chemotherapy received for metastatic disease is not allowed.
• Previous treatment with tyrosine kinase inhibitors or aromatase inhibitors is not allowed.
• Patients who have evidence of an active interstitial lung disease are not eligible.