DISEASE CHARACTERISTICS:

• Histologically confirmed breast cancer

  • Metastatic (stage IV) disease

• Relapsed after 1 of the following prior therapy regimens*:

  • Adjuvant therapy containing an anthracycline and a taxane
  • Adjuvant anthracycline therapy followed by first-line metastatic treatment containing a taxane NOTE: *No relapse within 12 months of initiation of prior therapy

• Measurable disease by CT scan or MRI

  • No ascites, pleural effusions, or osteoblastic bone metastases as the only site of measurable disease
• Refractory to hormonal anticancer therapy completed more than 4 weeks before study therapy

• HER2/neu positive allowed provided patient received prior trastuzumab (Herceptin®)

  • MUGA or echocardiogram normal while on trastuzumab
• No known history of or current brain or leptomeningeal metastases

• Hormone receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age

• Over 18

Sex

• Female

Menopausal status

• Not specified

Performance status

• ECOG 0-2

Life expectancy

• At least 12 weeks

Hematopoietic

• WBC at least 3,000/mm^3
• Neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 10.0 g/dL
• No clinically significant abnormal hematological parameters

Hepatic

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• Alkaline phosphatase no greater than 2.5 times ULN (5 times ULN in case of liver metastases)
• AST or ALT no greater than 2.5 times ULN (5 times ULN in case of liver metastases)

Renal

• Creatinine no greater than 1.5 times ULN

Cardiovascular

• See Disease Characteristics
• No myocardial infarction within the past 3 months
• No unstable angina pectoris
• No New York Heart Association class III or IV heart disease
• No uncontrolled arrhythmia
• No cardiac insufficiency
• No uncontrolled hypertension
• LVEF at least 50% OR at least lower limit of normal

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception 4 weeks before, during, and for at least 4 weeks after study participation
• No preexisting neuropathy (motor or sensory) greater than grade 2
• No clinically significant abnormal biochemical parameters
• No clinically significant active infection
• No other prior malignancy except cured nonmelanoma skin cancer or curatively treated carcinoma in situ of the cervix
• No other serious illness or medical condition
• No psychological illness or condition that would preclude study participation
• No other known condition that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Disease Characteristics
• More than 3 months since prior trastuzumab
• More than 2 weeks since prior growth factor therapy (i.e., filgrastim [G-CSF] or sargramostim [GM-CSF])
• No concurrent systemic anticancer immune modulators

Chemotherapy

• See Disease Characteristics

Endocrine therapy

• See Disease Characteristics
• More than 4 weeks since prior hormonal therapy
• No concurrent anticancer hormonal therapy

• No concurrent chronic systemic steroids

  • Concurrent topical or inhaled steroids for dermatological or allergy/asthma conditions allowed provided therapy was initiated prior to study enrollment
• Concurrent hormone replacement therapy allowed provided therapy was initiated prior to study enrollment

Radiotherapy

• More than 30 days since prior radiotherapy
• No concurrent radiotherapy directed at target lesions

Surgery

• At least 4 weeks since prior major surgery and recovered

Other

• More than 30 days since prior investigational new drug
• More than 2 weeks since prior blood transfusion
• No other concurrent systemic anticancer agents, including immunosuppressive agents
• No other concurrent investigational agents
• Concurrent bisphosphonates allowed provided therapy was initiated prior to study enrollment