A Randomized Phase III Study of SOX vs. COX in Patients With Advanced Colorectal Cancer
- The urgent need for new effective therapy with better safety profile for metastatic
colorectal cancer patients and promising results observed so far in trials with S-1
combined with oxaliplatin in gastrointestinal cancer including colorectal cancer
strongly warrants the comparison of S-1 combined with oxaliplatin to capecitabine
combination with oxaliplatin acknowledged as a standard regimen in a first-line
treatment for advanced colorectal cancer patients.
- Recently, a Phase I study was completed, indicating recommended dose as S-1 100
mg/m2/day1-14 and oxaliplatin (130 mg/m2/day1), repeated every 3 weeks. However, in the
phase II study using the above recommended dose, delayed toxicities of thrombocytopenia
and anemia were observed. These delayed toxicities were also reported in a phase II
study using S-1 90 mg/m2/day plus oxaliplatin 130 mg/m2/day1 in advanced gastric
cancer. At 2007 GI ASCO, the interim data of S-1(80 mg/m2/day1-14) plus oxaliplatin
(130 mg/m2/day1) combination, repeated every 3 weeks, was presented, showing promising
antitumor activity with favourable safety profile. Among 18 patients, there were only
two patients with Grade 3 thrombocytopenia and one with Grade 3 neutropenia. Response
rate was 57.1 % and disease control rate was 92.9 %. Considering these results and
Japanese data which showed that enhanced efficacy was not observed with S-1 over 90
mg/m2/day and oxaliplatin combination, S-1 80 mg/m2/day 1-14 and oxaliplatin 130
mg/m2/D1, repeated every 3 weeks, will be tested in this study.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
To compare the combination of S-1 and oxaliplatin to the combination of capecitabine and oxaliplatin in terms of progression free survival in patients previously untreated by systemic therapy for advanced or metastatic colorectal carcinoma.
Young Suk Park, M.D.,Ph.D.
Samsung Medical Center, Seoul, Korea
Korea: Food and Drug Administration