Protocol of OGSG 1901: a phase II trial of ramucirumab plus irinotecan for patients with early relapsed gastric cancer during or after adjuvant docetaxel plus S - 1 therapy.

Background: Although docetaxel plus S-1 adjuvant chemotherapy after gastrectomy with D2 lymphadenectomy has been a standard of treatment for stage III gastric cancer, there is no established chemotherapy for patients with recurrence during or within six months after the completion of adjuvant docetaxel plus S-1 therapy.

Methods: The OGSG 1901 trial is a prospective, open-label, multicenter, phase II trial evaluating ramucirumab plus irinotecan for gastric cancer patients with early relapse after adjuvant docetaxel plus S-1 therapy. The key eligibility criteria were: 1) histologically confirmed gastric adenocarcinoma 2) patients who were on docetaxel plus S-1 adjuvant chemotherapy after the confirmation of pathological stage III, 3) patients with early relapse, i.e., recurrence during or within 6 months after the completion of docetaxel plus S-1 therapy, and 4) patient with Eastern Cooperative Oncology Group performance status of 0-1. Irinotecan (150 mg/m, day 1) and ramucirumab (8 mg/kg, day 1) will be administered every 2 weeks. The primary endpoint is overall survival, and the secondary endpoints are overall response rate, progression-free survival, and safety. The number of patients has been set at 40 based on the threshold and expected median survival times of 7 and 11 months, respectively, with a one-sided alpha error of 0.05 and power of 0.80. The enrollment and follow-up periods are 2 and 1.5 years, respectively.

Discussion: The results of this trial will indicate whether the ramucirumab with irinotecan regimen has the potential to be a recommended treatment regimen for patients with recurrence gastric cancer during or within 6 months after the completion of adjuvant docetaxel plus S-1 therapy.

Trial Registration: This study was registered in the Japan Registry of Clinical Trials ( jRCTs05119071 , October 6, 2019).