Published in:
01-03-2007 | Original Article
Phase I and pharmacokinetic study of S-1 administered for 14 days in a 21-day cycle in patients with advanced upper gastrointestinal cancer
Authors:
Andrew X. Zhu, Jeffrey W. Clark, David P. Ryan, Jeffrey A. Meyerhardt, Peter C. Enzinger, Craig C. Earle, Charles S. Fuchs, Eileen Regan, Hiroshi Anbe, Michele Houghton, Joshua Zhang, Peter Urrea, Matthew H. Kulke
Published in:
Cancer Chemotherapy and Pharmacology
|
Issue 3/2007
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Abstract
Purpose
S-1 is a novel oral fluoropyrimidine that combines tegafur with CDHP and oxonic acid. To decrease the incidence of late onset, severe diarrhea observed in a previous study, a phase I study was conducted to determine the maximum tolerated dose (MTD) of S-1 utilizing a 14-day schedule, repeated every 21 days, in patients with chemotherapy–refractory upper gastrointestinal malignancies.
Methods
S-1 was administered orally, twice-daily, at an initial dose level of 30 mg/m2/dose; doses were escalated by 5 mg/m2 at each level. A minimum of three patients were enrolled at each dose level. S-1 toxicity, antitumor activity, and pharmacokinetics were assessed. The MTD was based on the dose limiting toxicity (DLT) during the first treatment cycle.
Results
At 30 mg/m2 no DLT was observed in the first three evaluable patients. Two of the first three patients at the 35 mg/m2 dose level developed DLTs (grade 3 rash and dehydration). An additional nine patients were subsequently treated at 30 mg/m2 without DLT and this dose was established as the MTD. Common toxicities at 30 mg/m2 included diarrhea, nausea, skin rash, anorexia, and fatigue. No grade 4 toxicities were observed. One partial response was seen in a patient with gemcitabine-refractory pancreatic adenocarcinoma and ten patients with pancreatic, gastric, or gallbladder carcinomas achieved stable disease as their best response to therapy. The AUC(0–8) of 5-FU at the 30 and 35 mg/m2 dose levels were 875 ± 212 and 894 ± 151 h ng/ml, respectively.
Conclusions
In a 14-day dosing schedule, the MTD of S-1 was 30 mg/m2 and preliminary evidence of antitumor activity was seen in a North American population with refractory upper gastrointestinal malignancies.