Stereotactic Radiation, Nelfinavir Mesylate & Neoadjuvant Chemotherapy in Locally Advanced Pancreatic Cancer

PRIMARY OBJECTIVES: I. To establish the safety, dose-limiting toxicities and maximally tolerated dose of hypofractionated stereotactic radiotherapy concurrently with nelfinavir in patients with locally advanced pancreatic cancer given as part of a neoadjuvant chemoradiation therapy regimen. SECONDARY OBJECTIVES: I. To evaluate the surgical complete resection rate. II. To evaluate the pathological response. III. To evaluate tumor response on computed tomography (CT)/magnetic resonance imaging (MRI). IV. To evaluate the correlation between the radiologic response and pathologic response. TERTIARY OBJECTIVES: I. To measure phospho-AKT expression in pancreatic tumor tissue prior to and following the neoadjuvant chemo-radiation program. (Correlative) II. To measure nelfinavir pharmacokinetics at steady-state. (Correlative) III. To measure the pharmacogenomic status of CYP2C19\*2 (G681A) in the study population. (Correlative) OUTLINE: This is a dose-escalation study of stereotactic radiotherapy (SRT) and concurrent nelfinavir mesylate. NEOADJUVANT THERAPY: Patients receive gemcitabine hydrochloride intravenously (IV) over 30 minutes, leucovorin calcium IV over 30 minutes, and fluorouracil IV continuously over 24 hours on days 1 and 8. Treatment repeats every 3 weeks for up to 3 courses in the absence of disease progression or unacceptable toxicity. Patients then receive nelfinavir mesylate orally (PO) twice daily (BID) beginning in week 9 and continuing until the completion of SRT or until 14 days after the completion of SRT. Patients undergo concurrent SRT once daily for 5 days in week 11. SURGERY AND ADJUVANT CHEMOTHERAPY: Approximately 2-3 weeks after completion of SRT, patients undergo restaging to evaluate disease response. Patients with resectable or potentially resectable disease and no metastasis undergo definitive surgery 2-3 weeks later. Approximately 1 month after surgery, these patients receive three additional courses of gemcitabine hydrochloride, leucovorin calcium, and fluorouracil as above. Patients with unresectable disease that is stable or responsive at the time of surgical exploration may resume treatment with gemcitabine hydrochloride, leucovorin calcium, and fluorouracil as above in the absence of disease progression or unacceptable toxicity. Patients with metastatic disease at the time of restaging are removed from the study. After completion of study treatment, patients are followed every 3 months for 1 year, every 4 months for 1 year, and then every 6 months thereafter.