A phase II trial of etoposide, leucovorin, 5-FU, and interferon alpha 2b (ELFI) plus G-CSF for patients with pancreatic adenocarcinoma: a Southwest Oncology Group study (SWOG 9413)

Background. Chemotherapeutic treatments using combinations of etoposide, leucovorin and 5-FU (ELF) have shown activity in the treatment of gastrointestinal malignancies. Interferon alpha 2b is known to have antiproliferative effects on several cell lines and has well documented in vitro evidence of synergism with 5-FU. It was postulated that the combination of ELF and interferon alpha 2b would improve response rates and survival in patients with pancreas cancer. Methods. Fifty-five eligible patients with locally-advanced or metastatic pancreatic adenocarcinoma received a regimen consisting of: IV leucovorin at 300 mg/m(2)/day on Days 1-3 (of 28-day cycle), IV etoposide at 80 mg/m(2)/day on Days 1-3, IV 5-FU at 500 mg/m(2)/day on Days 1-3, subcutaneous interferon alpha 2b at 3 million units TIW, and subcutaneous G-CSF at 5 mu g/kg/day on Days 4-14 (or until WBC exceeds 10,000/mu l). Patients with no evidence of disease progression continued on treatment for a total of 6 cycles. Results. Complete response was demonstrated in 1 patient, partial response in 5 patients (11% confirmed response rate). The median survival was 5 months, and the six-month survival rate was 40%. Ten patients completed all 6 cycles of treatment. Toxicity-related dose delays and reductions were necessary for most patients. Conclusions. Although the combination of ELF and interferon alpha 2b (ELFI) has modest activity in pancreatic cancer, it is a toxic and complex regimen that is not superior to other currently available approaches for the chemotherapeutic management of pancreatic cancer. ELFI cannot be recommended as a standard therapy.