Phase I study of S-1 combined with irinotecan (CPT-11) in patients with advanced gastric cancer (OGSG 0002).
OBJECTIVE
A dose-escalation study of irinotecan (CPT-11) combined with S-1, a novel oral fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD) and dose-limiting toxicities (DLTs) in advanced gastric cancer.


METHODS
S-1 was administered orally at 80 mg/m(2)/day for 21 consecutive days followed by a 2 week rest. CPT-11 was given intravenously on days 1 and 15 of each course, at an initial dose of 40 mg/m(2)/day, stepping up to 60, 80, 100 or 120 mg/m(2)/day depending on the DLT. Courses were repeated every 5 weeks, unless disease progression or severe toxicity was observed. At a level of the RD, five patients were added to conduct a pharmacokinetic (PK) study.


RESULTS
A total of 24 patients were entered in this study. The MTD of CPT-11 was considered to be 100 mg/m(2), because 50% of the patients (3/6) developed DLTs, diarrhea and rash. Therefore, the RD of CPT-11 was set at the dose immediately below 80 mg/m(2). The overall response rate (RR) by the criteria of the Japanese Research Society of Gastric Cancer was 58.3% (14/24) and the RR at the RD was 66.7% (6/9), suggesting promising clinical efficacy. There were no significant differences between the PK parameters of S-1 on days 10 and 15.


CONCLUSIONS
S-1 with CPT-11 can be combined safely without CPT-11 effect on S-1 PK data and holds promise as an effective regimen for advanced gastric cancer.
Takiuchi
Hiroya
H
Second Department of Internal Medicine, Osaka Medical College, Takatsuki, Osaka, Japan. in2028@poh.osaka-med.ac.jp
Narahara
Hiroyuki
H
Tsujinaka
Toshimasa
T
Gotoh
Masahiro
M
Kawabe
Sei-ichiro
S
Katsu
Ken-ichi
K
Iishi
Hiroyasu
H
Tatsuta
Masaharu
M
Fujitani
Kazumasa
K
Furukawa
Hiroshi
H
Taguchi
Tetsuo
T
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D004338:Drug Combinations; D005260:Female; D006801:Humans; D000077146:Irinotecan; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009367:Neoplasm Staging; D010094:Oxonic Acid / Q000008:administration & dosage / Q000009:adverse effects; D011725:Pyridines / Q000008:administration & dosage / Q000009:adverse effects; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology; D015996:Survival Rate; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects; D016896:Treatment Outcome
D004338:Drug Combinations; D011725:Pyridines; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D000077146:Irinotecan; D002166:Camptothecin