A Randomized, Double-Blind, Placebo-Controlled, Multicenter Phase III Study Comparing GW572016 and Letrozole Versus Letrozole in Subjects With Estrogen/Progesterone Receptor- Positive Advanced or Metastatic Breast Cancer

This study evaluated and compared the efficacy and tolerability of lapatinib and letrozole, with letrozole and placebo in post-menopausal women with hormone receptor positive (ER positive and/or PgR positive) advanced or metastatic breast cancer, who had not received prior therapy for advanced or metastatic disease.

本研究针对未接受过晚期或转移性疾病既往治疗的绝经后激素受体阳性（雌激素受体（ER）阳性且/或孕激素受体（PgR）阳性）晚期或转移性乳腺癌女性患者，评估并比较拉帕替尼（lapatinib）联合来曲唑（letrozole）与来曲唑联合安慰剂的疗效与耐受性。