Arsenic Trioxide in Treating Patients With Pancreatic Cancer That Has Not Responded to Gemcitabine

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed adenocarcinoma of the pancreas * Locally advanced or metastatic disease * Unidimensionally measurable disease * At least 1 lesion that is at least 20 mm with conventional techniques or at least 10 mm with spiral CT scan * Must have progressed after chemotherapy with a gemcitabine-containing regimen * No known brain metastases PATIENT CHARACTERISTICS: Age * Over 18 Performance status * ECOG 0-1 Life expectancy * Not specified Hematopoietic * WBC at least 3,000/mm\^3 * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 1.5 mg/dL * AST/ALT no greater than 5 times upper limit of normal Renal * Creatinine no greater than 1.5 mg/dL OR * Creatinine clearance at least 60 mL/min Cardiovascular * QTc less than 500 msec at baseline by EKG * No New York Heart Association class III or IV heart failure * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No prior allergic reactions attributed to compounds of similar chemical or biological composition to arsenic trioxide * No other active malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No other uncontrolled illness PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent immunotherapy * No concurrent colony-stimulating factors during the first course of the study Chemotherapy * See Disease Characteristics * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered * No prior arsenic trioxide * No other concurrent chemotherapy * No more than 1 prior chemotherapy regimen for metastatic disease Endocrine therapy * No concurrent hormonal therapy Radiotherapy * At least 4 weeks since prior radiotherapy and recovered * No concurrent therapeutic radiotherapy Surgery * At least 4 weeks since major surgery Other * No other concurrent investigational or commercial anticancer agents or therapies * No other concurrent investigational agents * No concurrent antiretroviral therapy in HIV-positive patients * No concurrent medications for other comorbid conditions that are known to prolong the QT interval