Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Any T, any N, M0

- Received prior therapy comprising one of the following regimens for primary prostate
cancer:

- External beam radiotherapy

- Brachytherapy with or without pelvic external beam radiotherapy

- Cryosurgery

- Radical prostatectomy with or without adjuvant or salvage radiotherapy

- Adjuvant or salvage radiotherapy after radical prostatectomy is allowed
provided the following criteria is met:

- PSA was never greater than 6.0 ng/mL

- At least 3 months since androgen deprivation

- Elevated PSA (0.4-6.0 ng/mL) that has increased on 2 measurements taken at least 2
weeks apart

- No history of or radiological evidence of current CNS disease (e.g., primary brain
tumor, seizures not controlled with standard medical therapy, or brain metastases)

PATIENT CHARACTERISTICS:

Performance status:

- ECOG 0-1

Life expectancy:

- At least 12 months

Hematopoietic:

- WBC greater than 2,500/mm^3

- Absolute neutrophil count greater than 1,000/mm^3

- Platelet count greater than 100,000/mm^3

- No prior bleeding disorder

Hepatic:

- Bilirubin no greater than 2 times upper limit of normal (ULN)

- AST no greater than 2 times ULN

- Hepatitis B and C negative

Renal:

- Creatinine no greater than 2 times ULN

- BUN no greater than 2 times ULN

Cardiovascular:

- No clinically significant cardiovascular disease

- No New York Heart Association grade II-IV heart disease (symptomatic congestive heart
failure)

- No unstable angina pectoris

- No serious cardiac arrhythmia requiring medication

- No uncontrolled hypertension

- No prior myocardial infarction

- No grade II or greater peripheral vascular disease within the past year

- No prior deep vein thrombosis

Other:

- Fertile patients must use effective contraception

- HIV and HTLV I and II negative

- No other uncontrolled illness, underlying medical condition, psychiatric illness, or
social situation that would preclude study participation

- No ongoing or active infection

- No active autoimmune disease requiring treatment

- No significant traumatic injury within the past 4 weeks

- No serious nonhealing wound, ulcer, or bone fracture

- No other "currently active" malignancy except nonmelanoma skin cancer

- Not "currently active" if considered by physician as having less than 30% risk
of relapse after completion of therapy

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No prior immunotherapy

- No prior anti-vascular endothelial growth factor therapy

Chemotherapy:

- No prior chemotherapy

Endocrine therapy:

- No prior hormonal therapy (e.g., luteinizing hormone-releasing hormone [LHRH]
agonists or antagonists, antiandrogens, estrogens, megestrol, or PC-SPES) for
progressive disease

- Prior hormonal therapy in adjuvant or neoadjuvant setting as primary therapy allowed
if at least 3 months since androgen deprivation

- No concurrent systemic steroid therapy (inhaled or topical steroids allowed)

Radiotherapy:

- No concurrent radiotherapy

Surgery:

- At least 4 weeks since prior major surgery, including open biopsy or needle biopsy of
liver

- No concurrent major surgery

Other:

- At least 10 days since prior aspirin

- At least 10 days since prior oral or parenteral anticoagulants except to maintain
patency of pre-existing permanent indwelling IV catheters

- No concurrent aspirin

- No concurrent oral or parenteral anticoagulants except to maintain patency of
pre-existing permanent indwelling IV catheters

- No other concurrent experimental or commercial agents or therapies for prostate
cancer