DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed solid tumor that is unresponsive to currently available therapies or for which no known effective therapy exists
• Overexpressing HER-2-neu (2+ or 3+) by immunohistochemistry or fluorescent in situ hybridization
• Clinically or radiologically evaluable disease

• No carcinomatous meningitis or untreated/uncontrolled metastatic brain parenchymal disease

  • At least 8 weeks since prior therapy for prior brain parenchymal disease and asymptomatic off corticosteroids

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 1.8 mg/dL
• ALT and AST no greater than 1.5 times upper limit of normal (ULN)

Renal:

• Creatinine no greater than 1.5 times ULN

Cardiovascular:

• No uncontrolled or significant cardiovascular disease
• No myocardial infarction within the past 6 months
• No prior clinically significant atrial or ventricular arrhythmias
• No prior second or third degree heart block
• No ischemic heart disease requiring medication
• No congestive heart failure
• Corrected QT interval no greater than 450 milliseconds by electrocardiogram
• Ejection fraction at least lower limit of normal by MUGA scan

Pulmonary:

• No uncontrolled or significant pulmonary disease

Other:

• No active unresolved infection
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 4 weeks since prior immunotherapy, including trastuzumab (Herceptin), and recovered

Chemotherapy:

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered
• No anthracyclines for at least 22 weeks after completion of study therapy
• No other concurrent chemotherapy

Endocrine therapy:

• See Disease Characteristics
• Concurrent hormone replacement therapy allowed
• No other concurrent hormonal therapy

Radiotherapy:

• At least 4 weeks since prior radiotherapy and recovered
• No prior radiotherapy to more than 25% of the bone marrow-containing skeleton
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• At least 4 weeks since prior investigational agents and recovered
• At least 7 days since prior known substrates of cytochrome P450-3A4 (CYP3A4)
• At least 7 days since prior parenteral antibiotics
• No concurrent substrates of CYP3A4
• No concurrent parenteral antibiotics
• No other concurrent experimental medications