Phase 1/2 clinical study of irinotecan and oral S-1 (IRIS) in patients with advanced gastric cancer.
BACKGROUND
Irinotecan and S-1, an oral fluoropyrimidine composed of tegafur, gimeracil, and oteracil potassium, have demonstrated antitumor activity against advanced gastric cancer. We performed a phase 1/2 study to determine the recommended dose, antitumor activity, and safety of a combination of S-1 and irinotecan in patients with advanced gastric cancer.


METHODS
Patients with previously untreated advanced gastric cancer were enrolled. Patients received irinotecan intravenously on days 1 and 15 plus oral S-1 twice daily on days 1-14 of a 28-day cycle. In the phase 1 part, the dose of irinotecan was escalated from 100 mg/m(2) to 125 mg/m(2) and then to 150 mg/m(2).


RESULTS
A total of 24 patients were enrolled. Overall, the median number of treatment cycles per patient was 5.9, and 92% of the patients completed at least two cycles. The overall response rate was 54.2% (13 of 24). The response rates in differentiated and undifferentiated cancer were 56.3% (nine of 16) and 50.0% (four of eight), respectively. Median survival time was 581 days. The maximum tolerated dose of irinotecan was not reached at the highest level. However, grade 4 neutropenia occurred at 125 mg/m(2). We concluded that the recommended dose of irinotecan for the present regimen was 125 mg/m(2).


CONCLUSIONS
Treatment with S-1+irinotecan is considered effective in patients with advanced gastric cancer who have not previously received chemotherapy. A combination of irinotecan and S-1 was well tolerated in patients with advanced gastric cancer and could be given on an outpatient basis.
Komatsu
Yoshito
Y
Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Hokkaido 060-8638, Japan. ykomatsu@med.hokudai.ac.jp
Yuki
Satoshi
S
Fuse
Nozomu
N
Kato
Takashi
T
Miyagishima
Takuto
T
Kudo
Mineo
M
Kunieda
Yasuyuki
Y
Tateyama
Miki
M
Wakahama
Osamu
O
Meguro
Takashi
T
Sakata
Yuh
Y
Asaka
Masahiro
M
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / 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; D008875:Middle Aged; D010094:Oxonic Acid / Q000008:administration & dosage / Q000009:adverse effects; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects; D055815:Young Adult
D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D000077146:Irinotecan; D002166:Camptothecin