DISEASE CHARACTERISTICS: Histologically or cytologically confirmed intraabdominal cancer Diffuse abdominal carcinomatosis Chemotherapy refractory advanced stage ovarian cancer Measurable disease Residual, recurrent, or metastatic disease beyond the scope of standard curative therapy Extension of disease to sites distant to the peritoneal cavity allowed Retroperitoneal lymphadenopathy allowed as long as there is evaluable intraabdominal disease No history of progressive brain metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: Hemoglobin greater than 9 g/dL WBC greater than 3,000/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin less than 2.0 mg/dL ALT less than 100 U/L Renal: Creatinine clearance greater than 60 mL/min Cardiovascular: Normal electrocardiogram No recent history of cardiac ischemia Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Hepatitis B negative No evidence of clinical immunodeficiency syndromes or immunodeficiency associated diseases No history of autoimmune disease No concurrent major illness No serious infection requiring intravenous antibiotics No active peptic ulcer disease Must have free flow of fluid into the peritoneal space No leakage from the catheter exit site

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 3 weeks since prior biologic therapy (6 weeks for interleukin-2) No prior recombinant human interleukin-12 Chemotherapy: See Disease Characteristics At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas) No concurrent systemic chemotherapy Endocrine therapy: No concurrent systemic corticosteroids Radiotherapy: No prior radiation therapy to the whole abdomen No concurrent radiotherapy Surgery: Not specified Other: At least 3 weeks since prior exposure to any investigational drug No concurrent investigational drug