Phase II Study of Herceptin (Recombinant Humanized Anti-p185HER2 Monoclonal Antibody) for the Treatment of Androgen Independent Prostate Cancer

Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically documented androgen dependent or independent
prostate cancer Progressive disease on primary hormonal treatment (e.g., orchiectomy,
estrogen therapy, gonadotropin releasing hormone analog with or without an antiandrogen)
New osseous lesions by bone scan OR 25% increase in bidimensionally measurable soft tissue
disease or appearance of new sites of disease by MRI or CT scan If initial hormonal
treatment was a combined androgen blockade approach, must show progression off of the
antiandrogen Minimum of 3 rising PSA values from baseline obtained 1 week or more apart OR
2 rising PSA values obtained 2 or more weeks apart PSA at least 4 ng/mL Testosterone no
greater than 30 ng/mL No active CNS or epidural tumor

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life
expectancy: At least 6 months Hematopoietic: WBC greater than 3,500/mm3 Platelet count
greater than 100,000/mm3 Hepatic: Bilirubin less than 2.0 mg/dL SGOT less than 3 times
upper limit of normal PT less than 14 seconds Renal: Creatinine less than 2.0 mg/dL OR
Creatinine clearance greater than 60 mL/min Cardiovascular: No myocardial infarction
within the prior 6 months No active angina pectoris, New York Heart Association class III
or IV heart disease, or severe debilitating valvular disease Ejection fraction greater
than 45%, with no evidence of ventricular aneurysm or other abnormal wall motion OR
SESTAMIBI stress test must show fixed defect alone if ejection fraction less than 45%, or
a worrisome but nonexclusive cardiovascular history, or an abnormal ECG Pulmonary: No
severe pulmonary disease Other: Fertile patients must use effective contraception No
history of an active secondary malignancy with the past 5 years except nonmelanoma skin
cancer No infection requiring intravenous antibiotic treatment No other severe medical
problem that would increase the risk for toxicity

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent immunotherapy Chemotherapy: At
least 4 weeks since prior chemotherapy and recovered No concurrent chemotherapy Endocrine
therapy: See Disease Characteristics If no prior surgical orchiectomy, must continue
medical therapies to maintain castrate levels of testosterone Radiotherapy: At least 4
weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: See
Disease Characteristics and Endocrine therapy No concurrent surgery Other: At least 4
weeks since other prior investigational anticancer therapeutic drugs and recovered No
prior anthracycline or anthracenedione No concurrent investigational or unlicensed agents
No other concurrent oncolytic agent