Inclusion Criteria:
- Histologically or cytologically confirmed metastatic breast cancer
- Documented expression of CD117 (c-kit) or platelet-derived growth factor receptor
- Adequate tumor tissue from either the primary tumor and/or metastatic disease
available for evaluation
- Must have received prior chemotherapy with an anthracycline (doxorubicin or
epirubicin) and/or taxane (paclitaxel or docetaxel) as adjuvant or for advanced
disease
- At least 1 unidimensionally measurable lesion
- At least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan
- Bone disease may not be only source of measurable disease
- Pleural or peritoneal ascites are not considered measurable disease
- No known brain metastases
- Hormone receptor status:
- Not specified
- Female or male
- Not specified
- Performance status - ECOG 0-2
- Performance status - Karnofsky 60-100%
- More than 12 weeks
- Absolute neutrophil count at least 1,500/mm^3
- WBC at least 3,000/mm^3
- Platelet count at least 100,000/mm^3
- Bilirubin normal
- AST or ALT no greater than 2.5 times upper limit of normal
- Creatinine normal
- Creatinine clearance at least 60 mL/min
- No symptomatic congestive heart failure
- No unstable angina pectoris
- No cardiac arrhythmia
- No other uncontrolled concurrent illness
- No ongoing or active infection
- No prior allergic reaction attributed to compounds of similar chemical or biologic
composition to imatinib mesylate
- No other malignancy within the past 5 years except basal cell skin cancer or
carcinoma in situ of the cervix
- No psychiatric illness or social situation that would preclude study compliance
- Not pregnant or nursing
- Negative pregnancy test
- Fertile patients must use effective barrier contraception during and for 1 week
after study
- No concurrent biologic agents
- No more than 2 prior chemotherapy regimens for metastatic disease
- Therapy with high-dose regimens or bone marrow transplantation considered 1
regimen
- At least 4 weeks since prior chemotherapy (6 weeks for carmustine or mitomycin) and
recovered
- No concurrent chemotherapy
- Prior hormonal therapy for stage IV disease and/or as adjuvant therapy allowed
- At least 4 weeks since prior radiotherapy and recovered
- Prior localized radiotherapy that does not influence the signal of the evaluable
lesion is allowed
- At least 2 weeks since prior minor surgery
- At least 4 weeks since prior major surgery
- Recovered from prior surgery
- Low-molecular weight heparin or heparin allowed for anticoagulation
- No concurrent warfarin
- No concurrent combination antiretroviral therapy for HIV-positive patients
- No concurrent investigational therapies or agents
- No other concurrent anticancer therapy
- No concurrent intake of cola, orange juice, grapefruit, or orange or grapefruit
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