Irinotecan/gemcitabine followed by twice-weekly gemcitabine/radiation in locally advanced pancreatic cancer

Abstract

Early clinical studies combining irinotecan (CPT-11, Camptosar) and gemcitabine (Gemzar) have yielded encouraging results. Gemcitabine administered via a twice-weekly schedule results in an enhanced radiation-sensitizing effect. This multi-institution phase II trial of induction irinotecan/gemcitabine followed by twice-weekly gemcitabine and upper abdominal radiation has been initiated to determine the activity of this regimen in patients with unresectable pancreatic cancer. Patients received two cycles of induction irinotecan (100 mg/ m2 IV) and gemcitabine (1,000 mg/m2 IV) on days 1 and 8 of each 3-week cycle. Following the induction therapy, patients without disease progression received twice-weekly gemcitabine at 40 mg/m2 and radiation. Nine patients have been enrolled in the study to date. Median patient age was 71 years (range: 65-85 years). The major toxicity observed thus far was grade 3/4 neutropenia. Grade 3/4 nonhematologic toxicity was rarely observed and included dehydration (12%) and diarrhea (12%), which were likely related to the irinotecan. No treatment-related deaths have occurred. These preliminary data suggest that this regimen is well tolerated. Although the data are limited, tumor progression during the induction chemotherapy has not been observed thus far (radiographically or biochemically [CA-19-9]).