Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically proven locally recurrent organ-confined prostate
cancer after external beam radiotherapy, radiation seed implants, or cryosurgery Gleason
score at least 6 PSA at least 1.0 ng/mL with 2 consecutive rises in PSA at least 2 weeks
apart, of which the second increase is greater than the first, after achieving a nadir
Must have at least 3 recorded PSA values over a minimum of the last 3 months to determine
the slope Patients must have declined additional conventional treatment or be ineligible
for conventional treatment of their prostate cancer No metastasis by bone scan No
significant CNS disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 80-100% OR ECOG 0
or 1 Life expectancy: Not specified Hematopoietic: WBC greater than 3,000/mm3 Platelet
count greater than 100,000/mm3 Hemoglobin greater than 9.0 g/dL Hepatic: Bilirubin normal
SGOT or SGPT less than 3 times upper limit of normal Albumin greater than 3 g/dL PT and
PTT normal Hepatitis B surface antigen negative Renal: Creatinine normal Cardiovascular:
No uncontrolled hypertension No significant cardiovascular disease, e.g.: History of
ventricular dysfunction Congestive heart failure Symptoms of coronary artery disease
History of any ventricular arrhythmia Prior myocardial infarction Other: HIV negative
Fertile patients must use effective double-barrier contraception during and for 3 months
after study participation No active autoimmune disease No active infection requiring IV
antibiotics No uncontrolled diabetes mellitus No significant psychiatric disorder that
would preclude study No other malignancy within the past 5 years except adequately treated
basal cell or squamous cell skin cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior leuvectin Chemotherapy: At least 3
weeks since prior chemotherapy (6 weeks for mitomycin or hydroxyurea) Endocrine therapy:
No prior hormonal therapy for prostate cancer Radiotherapy: See Disease Characteristics At
least 3 weeks since prior radiotherapy Surgery: At least 1 month since prior intrathoracic
or intra-abdominal surgery At least 2 weeks since other prior major surgery Other: At
least 10 days since prior anticoagulants or non-steroidal anti-inflammatory agents No
neoadjuvant or other concurrent anticancer drug therapy No concurrent immunosuppressive
drugs No other concurrent experimental therapy