Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of prostate cancer with rising PSA values without metastasis

- PSA must be at least 5 ng/mL

- PSA must show an increase above a reference level on 2 separate occasions

- Must have tumor over-expressing epidermal growth factor receptor (EGFr) by
immunohistochemistry

- Staining must be 2+ or 3+ in at least 10% of evaluated tumor cells

- Must have tissue available for diagnostics

- Must have failed prior front-line luteinizing hormone-releasing hormone (LHRH)
analogue (e.g., leuprolide or goserelin) OR failed orchiectomy and have castrate
levels of testosterone (less than 50 mg/mL) NOTE: Must continue on a LHRH analogue
(unless an orchiectomy was performed) throughout the study

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-1

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count greater than 1,500/mm^3

- Platelet count at least 100,000/mm^3

Hepatic

- Bilirubin no greater than 1.5 times upper limit of normal (ULN)

- Alkaline phosphatase no greater than 3 times ULN

- AST and ALT no greater than 3 times ULN

Renal

- Creatinine less then 2.2 mg/dL

- Calcium no greater than ULN

Cardiovascular

- Left ventricular ejection fraction at least 45% by MUGA

- No myocardial infarction within the past year

Other

- HIV negative

- Fertile patients must use effective contraception during and for 1 month after study

- No other malignancy within the past 5 years except basal cell carcinoma

- No history of chronic medical or psychiatric condition or laboratory abnormality that
would preclude study participation, administration, or interpretation

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- Not specified

Endocrine therapy

- See Disease Characteristics

- At least 6 weeks since prior steroidal or nonsteroidal antiandrogens (4 weeks for
flutamide)

- Concurrent steroid therapy allowed as replacement therapy only

Radiotherapy

- Not specified

Surgery

- See Disease Characteristics

Other

- At least 30 days since prior investigational therapy

- At least 30 days since prior anticancer therapy

- No prior systemic therapy for prostate cancer (except hormonal therapy)

- No prior anti-EGFr therapy

- Concurrent antihypercalcemic treatment allowed in the presence of elevated calcium
levels but not as cancer therapy for bone disease

- No other concurrent anti-EGFr therapy

- No other concurrent anticancer therapy

- No other concurrent investigational therapy