Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed prostate cancer

- Disease progression after prior castration

- At least 3 rising PSA levels at least 1 week apart OR 2 rising levels at least 4
weeks apart

- New osseous lesions on bone scan and/or more than 25% increase in bidimensionally
measurable soft tissue disease or appearance of new sites of disease by CT scan or
MRI

- Testosterone no greater than 50 ng/mL

- Medical therapy (e.g., gonadotropin-releasing hormone analogues) to maintain
castrate level of testosterone should continue in the absence of surgical
orchiectomy

- Progression of disease after discontinuation of prior anti-androgen therapy

- No requirement for palliative therapy within the past 12 weeks

- No active CNS or epidural primary tumor OR active CNS or epidural metastases

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Karnofsky 60-100%

Life expectancy:

- Not specified

Hematopoietic:

- WBC greater than 3,500/mm3

- Platelet count greater than 100,000/mm3

Hepatic:

- Bilirubin less than 1.5 mg/dL

- Gamma-glutamyl-transferase less than upper limit of normal (ULN)

- AST less than ULN

- PT less than 14 seconds

- No prior autoimmune hepatitis

Renal:

- Creatinine less than 1.5 mg/dL OR

- Creatinine clearance greater than 60 mL/min

Cardiovascular:

- No clinically significant cardiac disease (New York Heart Association class III or
IV)

Pulmonary:

- No severe debilitating pulmonary disease

Other:

- Fertile patients must use effective contraception

- No active uncontrolled infection or infection requiring IV antibiotics

- No prior autoimmune disease

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No prior murine protein for diagnostic or therapeutic purposes

- No other concurrent anticancer immunotherapy

Chemotherapy:

- At least 4 weeks since prior chemotherapy and recovered

- No concurrent anticancer chemotherapy

Endocrine therapy:

- See Disease Characteristics

- No concurrent anticancer hormonal therapy

Radiotherapy:

- At least 4 weeks since prior radiotherapy and recovered

- Concurrent radiotherapy to localized sites of disease (e.g., bone) allowed if the
site does not contain sole measurable lesion

Surgery:

- See Disease Characteristics

- No concurrent surgery

Other:

- Recovered from all prior therapy

- At least 4 weeks since prior therapeutic investigational anticancer drugs

- At least 4 weeks since prior participation in therapeutic clinical trial with an
experimental drug

- No prior diagnostic ProstaScint, Myoscint, or Oncoscint scans

- No other concurrent therapeutic investigational anticancer agents

- No concurrent participation in other therapeutic clinical trial with an experimental
drug