Phase I Study of Oxaliplatin, Full-Dose Gemcitabine, and Concurrent Radiation Therapy in Pancreatic Cancer

Abstract

To determine a biweekly dose of oxaliplatin for combination with full-dose gemcitabine and concurrent radiation therapy (RT) in pancreatic cancer. Patients with previously untreated pancreatic cancer received gemcitabine days 1, 8, and 15, and oxaliplatin days 1 and 15, repeated at 28-day intervals. RT (27 Gy in 1.8-Gy fractions) was administered during cycle 1. Dose escalation was guided using the time-to-event continuous reassessment method. Dose levels 1 to 4 included gemcitabine 1 g/m2 intravenously (IV) during 30 minutes and oxaliplatin 40, 55, 70, or 85 mg/m2 IV during 90 minutes, respectively; for dose levels 5 and 6, oxaliplatin dose remained 85 mg/m2 but infusion time for gemcitabine 1 g/m2 was increased to 65 or 100 minutes, respectively. The trial objective was to determine the dose level associated with dose-limiting toxicity (DLT) through cycle 2 in < or = 20% of patients. Forty-four patients were enrolled (median age, 64 years; 27 men, 17 women) with resectable (n = 12), unresectable (n = 29), and metastatic (n = 3) pancreatic cancer. Ten DLTs occurred in nine patients, including grade 4 platelets (n = 4), decline in performance status (n = 2), GI bleeding (n = 2), and GI toxicity (n = 2). The estimated probability of DLT for dose level 3 was .21 (90% posterior probability interval [PI], .12 to .33); for dose level 4, the estimated probability was .24 (90% PI, .14 to .36). The addition of oxaliplatin 85 mg/m2 days 1 and 15 to full-dose gemcitabine and radiation therapy was well tolerated. On the basis of these results, a multi-institutional neoadjuvant phase II study in resectable pancreatic cancer is planned.