Gut microbiota dynamics of antibiotic fecal microbiota transplantation in esophageal and gastric cancer patients treated with immune checkpoint inhibitors: Preliminary results from the Biorich2 study.

作者：Shotaro Yamaguchi, Yuri Yoshinami, Hirokazu Shoji, Natsuko Okita, Hiroyuki Takamaru, Toshiharu Hirose, Hidekazu Hirano, Atsuo Takashima, Hiroshi Imazeki, Shun Yamamoto, Shohei Koyama, Jun Adachi, Dai Ishikawa, Ryo Hasegawa, Misa Imai, Kana Ogawa, Hikaru Watanabe, Ken Kato, Kazuki Tanaka, Haruka Sato · 发表于：Journal of Clinical Oncology · 年份：2026 · DOI：10.1200/jco.2026.44.16_suppl.e16030 · 研究领域：Gut microbiota and health、Clostridium difficile and Clostridium perfringens research、Cancer Immunotherapy and Biomarkers

e16030 Background: Despite advances in immune checkpoint inhibitor (ICI)–based therapy, outcomes for patients with unresectable or recurrent esophageal and gastric cancers remain poor. The gut microbiome has emerged as a determinant of response to ICI, and modulation of the gut microbiome through fecal microbiota transplantation (FMT) has shown potential to improve ICI efficacy. We conducted a phase I/II study to evaluate the safety, feasibility, and efficacy of FMT with antibiotic pretreatment (A-FMT) combined with ICI-based regimens in patients with esophageal squamous cell carcinoma (ESCC) and gastric/gastroesophageal junction (G/GEJ) adenocarcinoma. Methods: The study consists of a safety part and an expansion part. Patients receive a 1-week course of oral antibiotics (amoxicillin, fosfomycin, and metronidazole), followed by a single donor-derived FMT via colonoscopy. ICI-based therapy is initiated the day after A-FMT. For ESCC, regimens included nivolumab (3 mg/kg) plus ipilimumab (1 mg/kg), or fluorouracil (800 mg/m 2 ) plus cisplatin (80 mg/m 2 ) [CF] combined with pembrolizumab (200 mg/body). For G/GEJ cancer, the regimen consisted of oxaliplatin (130 mg/m 2 ) plus S-1 (40 mg/m 2 ) [SOX] combined with nivolumab (360 mg/body). The primary endpoint was the incidence of dose-limiting toxicities (DLTs) within 28 days after FMT. DLTs were defined as any grade 3 or higher non-hematological toxicity related to FMT. Secondary endpoints included efficacy outcomes and incidence...