Phase II study of combined chemotherapy with irinotecan and S-1 (IRIS) plus bevacizumab in patients with inoperable recurrent or advanced colorectal cancer

Background. In Japan, a study comparing the effectiveness and safety of irinotecan plus S-1 (IRIS) with those of a combination of 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) as second-line treatment in patients with advanced or recurrent colorectal cancer demonstrated that IRIS was non-inferior to FOLFIRI. We previously reported that IRIS is also effective as first-line treatment. Patients and Methods. Eligibility criteria included inoperable recurrent colorectal cancer with a confirmed diagnosis of adenocarcinoma, age ≥ 20 years, and no history of prior chemotherapy. S-1 (40-60 mg twice daily) was given orally on days 1 to 14, and irinotecan (100 mg/m2) and bevacizumab (5 mg/kg) were given intravenously on days 1 and 15 of a 28-day cycle. The primary endpoint was safety. The secondary endpoints included overall response (OR), progression-free survival (PFS), and overall survival (OS). Results. A total of 52 eligible patients were enrolled from October 2007 through March 2009. In safety analysis, the incidences of grade 3 or 4 adverse reactions were as follows: neutropenia, 27%; hypertension, 21%; and diarrhea, 17%. The overall response rate was 57.7%. Median progression-free survival was 16.7 months. Conclusion. IRIS plus bevacizumab is a well-tolerated, highly effective chemotherapeutic regimen that is easy to administer

Study protocol of HGCSG1404 SNOW study : a phase I/II trial of combined chemotherapy of S-1, nab-paclitaxel and oxaliplatin administered biweekly to patients with advanced gastric cancer

Background: In Japan, S-1 plus cisplatin (SP) regimen has become a standard therapy for patients with advanced gastric cancer. Moreover, the S-1 plus oxaliplatin regimen is now a standard treatment. Nab-paclitaxel was developed for chemotherapy of gastric cancer in Japanese clinical practice. Nab-paclitaxel, created with albumin-bound paclitaxel particles, has high transferability to tumour tissues and does not cause hypersensitivity reactions because of a different chemical composition compared with docetaxel and paclitaxel. A combination of S-1, nab-paclitaxel and oxaliplatin (which we named ‘SNOW regimen’) can be a promising triplet therapy for advanced gastric cancer. Although we have to pay attention to chemotherapy-induced neuropathy, we aim to investigate the recommended dose of this regimen in a phase I study. Furthermore, we will investigate its efficacy and toxicity in a phase II study. Methods: The phase I study is a dose-escalation study using a standard 3 plus 3 design, followed by expansion cohorts. The SNOW regimen involves 28-day cycles with escalated doses of nab-paclitaxel (100-175 mg/m2 on days 1 and 15) and fixed doses of oxaliplatin (65 mg/ m2 on days 1 and 15) and S-1 (80 mg/m2/day on day 1 to 14). The primary endpoints are assessment of dose limiting toxicities and determination of maximum tolerated dose to investigate the recommended dose in the subsequent phase II study. In the phase II study, the primary endpoint is objective response rate. Secondary endpoints are assessment of safety, progression-free survival, disease control rate, overall survival and time to treatment failure. Adverse events were monitored and graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Discussion: Triplet therapies for advanced gastric cancer patients have been evaluated in clinical trials. The SNOW regimen can be a promising new triplet therapy. Trial registration: This study is performed at institutes that participate in Hokkaido Gastrointestinal Cancer Study Group (HGCSG) and registered as UMIN000016788. Registrated 16 March 2015