Lapatinib In Chemotherapy-Naive Or Metastatic Breast Cancer

A Phase II, Open-Label, Randomized, Parallel-Group Multicenter Trial Comparing Two Schedules of GW572016 as First-Line Monotherapy in Patients With Advanced or Metastatic Breast Cancer

This phase II study will evaluate and compare the efficacy and tolerability of two dose schedules (1500 mg QD and 500 mg BID) of oral Lapatinib as treatment for patients with advanced or metastatic breast cancer.

Inclusion criteria:

• Histologically confirmed invasive breast cancer with incurable stage IIIB, IIIC with T4 lesion or stage IV disease at primary diagnosis or at relapse after curative intent surgery.
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
• Documented amplification of ErbB2 by Fluorescence in situ hybridization (FISH)
• Measurable disease by Response Evaluation Criteria In Solid Tumors (RECIST)
• Adequate renal, hepatic and cardiac function

Exclusion criteria:

• Prior chemotherapy, immunotherapy, biologic therapy or anti-ErbB1/ErbB2 therapy other than adjuvant therapy. [Prior neo-adjuvant or adjuvant therapy (including trastuzumab) will be allowed provided it was stopped at least 12 months before study entry.
• Patients with active brain metastases
• Patients with bilateral breast cancer, bone metastases as the only disease site or metastases to more than 30% of the hepatic parenchyma.