Erlotinib and Gemcitabine With or Without Panitumumab in Treating Patients With Metastatic Pancreatic Cancer

OBJECTIVES: Primary * To assess whether the addition of panitumumab (a dual-epidermal growth factor receptor inhibitor) to standard chemotherapy comprising gemcitabine hydrochloride and erlotinib hydrochloride results in an improvement in overall survival of patients with previously untreated, metastatic adenocarcinoma of the pancreas. Secondary * To compare objective response rates, progression-free survival, time to treatment failure, quality of life, and adverse event rates in patients treated with these regimens. * To evaluate the downstream marker, KRAS, in stool specimens. OUTLINE: This is a multicenter study. Patients are stratified according to ECOG performance status (0 vs 1) and prior adjuvant chemotherapy (yes vs no). The first 6 patients are assigned to arm II. Subsequent patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive gemcitabine hydrochloride IV over 30 minutes on days 1, 8, and 15 and oral erlotinib hydrochloride once daily on days 1-28. Treatment repeats every 28 days for 2 courses. Patients achieving a complete response (CR) after 2 courses receive 2 additional courses of treatment; patients achieving a partial response (PR) receive retreatment as above in the absence of disease progression or unacceptable toxicity. Patients achieving a CR after 4 courses of treatment receive maintenance therapy comprising erlotinib hydrochloride daily until the first disease progression. After the first progression, patients are retreated with gemcitabine hydrochloride and erlotinib hydrochloride until second progression (using the first progression tumor measurements as the new baseline reference). * Arm II: Patients receive gemcitabine hydrochloride and erlotinib hydrochloride as in arm I and panitumumab IV over 1 hour on days 1 and 15. Treatment repeats every 28 days for 2 courses. Patients achieving a CR after 2 courses receive 2 additional courses of treatment; patients achieving a PR receive retreatment as above in the absence of disease progression or unacceptable toxicity. Patients achieving a CR after 4 courses of treatment receive maintenance therapy comprising erlotinib hydrochloride daily and panitumumab every 2 weeks until the first disease progression. After the first progression, patients are retreated with gemcitabine hydrochloride, erlotinib hydrochloride, and panitumumab until second progression (using the first progression tumor measurements as the new baseline reference). Stool samples are collected at baseline and analyzed for KRAS mutations via protein analyses. Quality of life will be assessed at baseline, every 2 courses during treatment, and at the end of treatment. After the second progression, patients are followed every 3-6 months for 2 years.