OBJECTIVES:

• Determine the pharmacokinetics and pharmacodynamics of trastuzumab (Herceptin) and paclitaxel in patients with HER2-overexpressing metastatic breast cancer.
• Provide access to trastuzumab and paclitaxel for these patients.

OUTLINE: Patients receive trastuzumab (Herceptin) IV over 30-90 minutes and paclitaxel IV over 1 hour weekly. Patients receive trastuzumab alone during course 1 and then in combination with paclitaxel during subsequent courses. Courses repeat every 4 weeks until patients achieve a sustained complete response of 8 weeks or disease progression occurs.

PROJECTED ACCRUAL: A total of 55 patients will be accrued for this study within 2 years.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed metastatic breast cancer with HER2 overexpression
• Radiographically or physically measurable disease that can be biopsied safely under local anesthesia

• Hormone receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Sex:

• Male or female

Menopausal status:

• Not specified

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Neutrophil count at least 1,000/mm^3
• Platelet count at least 75,000/mm^3

Hepatic:

• Bilirubin no greater than 3 times upper limit of normal (ULN)
• AST and ALT no greater than 5 times ULN

Renal:

• Not specified

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior trastuzumab

Chemotherapy:

• Not specified

Endocrine therapy:

• At least 2 weeks since prior hormonal therapy
• No concurrent hormone receptor therapy (e.g., tamoxifen or armidex)

Radiotherapy:

• Localized palliative external beam radiotherapy allowed

Surgery:

• Not specified

Other:

• Concurrent bisphosphonates allowed