AZD0530 and Gemcitabine in Locally Advanced/Metastatic Pancreatic Cancer That Cannot Be Removed By Surgery

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed pancreatic adenocarcinoma * Unresectable disease * Locally advanced or metastatic disease * Clinically or radiologically documented disease * Measurable or evaluable disease (phase I) * Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan (phase II) * Measurable lesion must be outside of previously irradiated field if it is the sole site of disease unless there is documented disease progression * No known brain metastases PATIENT CHARACTERISTICS: Performance status * ECOG 0-2 Life expectancy * More than 12 weeks Hematopoietic * Platelet count ≥ 100,000/mm\^3 * Absolute granulocyte count ≥ 1,500/mm\^3 Hepatic * Bilirubin normal * AST and ALT ≤ 2 times upper limit of normal (ULN) (5 times ULN if clearly attributable to liver metastasis) Renal * Creatinine normal Cardiovascular * No active cardiomyopathy * No congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia * No uncontrolled hypertension * No myocardial infarction within the past 12 months Pulmonary * No pulmonary disease requiring oxygen supplementation Gastrointestinal * Must not require IV hyperalimentation * No uncontrolled inflammatory gastrointestinal (GI) disease (e.g., Crohn's disease or ulcerative colitis) * No active peptic ulcer disease * No postsurgical malabsorption characterized by uncontrolled diarrhea that results in weight loss and vitamin deficiency * No other GI tract disease resulting in an inability to take oral medications * Must be able to take oral medication without crushing, dissolving, or chewing tablets * Pancreatic enzyme supplementation allowed provided the above conditions are met Immunologic * No immune deficiency * No active, uncontrolled, or serious infection * No know hypersensitivity to study drugs or their components * No known HIV positivity Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No history of psychiatric illness (e.g., uncontrolled psychotic disorders) or neurologic disorder that would preclude study compliance * No other serious medical condition or illness that would preclude study participation * No other malignancy within the past 5 years except curatively treated nonmelanomatous skin cancer or carcinoma in situ of the cervix or bladder PRIOR CONCURRENT THERAPY: Chemotherapy * No prior chemotherapy except fluorouracil (with or without leucovorin calcium) or gemcitabine given concurrently with radiotherapy as a radiosensitizer * At least 4 weeks since prior fluorouracil or gemcitabine Endocrine therapy * Concurrent systemic hormonal therapy for symptom control (e.g., appetite stimulation, pain, or nausea) allowed Radiotherapy * See Disease Characteristics * See Chemotherapy * At least 4 weeks since prior radiotherapy for local disease and recovered Surgery * At least 3 weeks since prior major surgery Other * At least 2 weeks since prior anticancer therapy or investigational agents * The following drugs must not be used for 1-2 weeks before, during, and for 1-2 weeks after completion of study treatment: * Ketoconazole * Itraconazole * Ritonavir * Mibefradil * Clarithromycin * Saquinavir mesylate * Indinavir sulfate * Erythromycin * Nefazodone hydrochloride * Fluconazole * Diltiazem hydrochloride * Alfentanil hydrochloride * Carbamazepine * Cyclosporine * Tacrolimus * Lovastatin * Simvastatin * Any other drug known to be a potent inhibitor of cytochrome 3A4 * No other concurrent anticancer therapy or investigational agents