The combination of irinotecan(Drug information on irinotecan) (CPT-11, Camptosar) and gemcitabine(Drug information on gemcitabine) (Gemzar) produced a 1-year survival rate of 27%, which is greater than that reported for gemcitabine alone in previous studies in patients with advanced pancreatic cancer (15% and 18% 1-year survival rates, respectively). These study results were published in a recent issue of the Journal of Clinical Oncology (20:1182-1191, 2002).
"The findings suggest that the addition of irinotecan to gemcitabine may enhance the clinical benefit of gemcitabine as well as increase survival in a disease in which 8 out of 10 patients die within a year of being diagnosed," said Caio Max S. Rocha Lima, MD, assistant professor of medicine, University of South Florida, H. Lee Moffitt Cancer Center & Research Institute. "Irinotecan, the standard of care for the treatment of advanced colorectal cancer, is showing promise in this difficult tumor type and is offering hope to patients with this devastating disease."
Two previous phase II studies have demonstrated that irinotecan alone has antitumor activity in pancreatic cancer. Gemcitabine is considered the standard of care for this disease. Studies have shown it demonstrates positive clinical and tumor response rates and improves median and 1-year survival.
The current phase II, multicenter, open-label, single-arm study evaluated the efficacy and safety of irinotecan plus gemcitabine in 45 patients with previously untreated, unresectable, or metastatic pancreatic cancer. Median survival in patients treated with the combination was 5.7 months (range: 0.4-19.4+ months). Patients also experienced a favorable tumor response rate (tumor size decreased by ³ 50%) compared to the conventional rates reported for single-agent therapy. In addition, the combination was well tolerated, with minimal severe toxicity.
Study participants received repeated 21-day cycles of gemcitabine, 1,000 mg/m² for 30 minutes, followed by irinotecan, 100 mg/m² for 90 minutes, administered intravenously on days 1 and 8. The study’s end points included objective tumor response rate, time to tumor progression, and survival.
"The study findings are significant because patients with pancreatic cancer often are severely debilitated," said Dr. Rocha Lima. "We are encouraged by these data that show that the combination was safe, and demonstrated notable 1-year survival. Based on these results, we have initiated a phase III study, which is now fully accrued and which will allow further evaluation of this combination therapy."