PD-1 inhibitor (sintilimab) and fruquintinib plus SOX as conversion therapy for initially unresectable gastric/gastroesophageal junction adenocarcinoma (GC/GEJC): Updated results from a single-arm, phase 2 clinical trial.

• DOI: 10.1200/jco.2025.43.4_suppl.406
• Publication Date: 2025-01-27T14:34:47Z
• Authors: Fei Ma; Suxia Luo; Bin Zhang; Qi Ma; Sheqing Ji; Zhandong Zhang; Yonglei Zhang; Wei Yang; Liangqun Peng; Dandan Guo; Jinjun Ren; Yuan Zhang; Yueyue Su; Jing Li; Wentao Liu; Jinxi Huang; Weiwei Yuan
• Keywords: Gastric adenocarcinoma

406 Background: The evidence of conversion therapy for unresectable GC/GEJC is limited. Previously, preliminary results the ongoing open-label, phase 2 study (NCT05177068) have showed promising R0 surgical rate (62.1%), resection (100%) and acceptable tolerability in with sintilimab fruquintinib plus SOX (ASCO 2024). Here we present updated longer follow-up duration, including more enrolled patients. Methods: Eligible patients were administered (4mg/d, po, qd, d1-14), (200mg, iv, d1), oxaliplatin (130 mg/m , d1) S-1 (40-60mg based on BSA, bid, d1-14) every 3 weeks or 6 cycles. One cycle was given before resection. Patients assessed tumor response feasibility by radiologic imaging & MDT Primary endpoint rate. Secondary endpoints included pathological response, ORR, PFS, OS, safety. Results: As July 30, 2024, 42 pts (37 males/5 females) a median age 64 years (range: 43–76), 71% ECOG PS1, 55% GEJC enrolled. Nine (21.4%) had distant metastasis five (11.9%) than one factors. most common factors extensive bulky lymph nodes 54.8% (23), liver 11.9% (5), peritoneal 4.8% (2), para-aortic node 2.4% (1), local progression 38.1% (16). Of 35 evaluable pts, ORR 68.6% DCR 97.1%. Among 29 who completed conversion, 100% (29/29) 82.9% (29/35). 10.3% (3/29) achieved complete (pCR), 20.7% (6/29) reached regression grade (TRG) 0-1. Additionally, (pRR) according to JCGC (≥ Grade 1b) 93.1% (27/29). Seven (16.7%) treatment-emergent adverse events, 4 cases anemia, neutrophil count decreased, 1 case each (lymphocyte gastrointestinal hemorrhage, diarrhea, immune-related pneumonitis). No severe surgery-related complication observed. Conclusions: Fruquintinib combined yielded very high manageable safety profile GC/GEJC, representing potential feasible regimen this population. Survival data will continue be followed up. Clinical trial information: NCT05177068 .