Clinical Efficacy and Safety of Apatinib Combined with Irinotecan in HER2-negative Patients with Advanced Gastric or Gastroesophageal Junction Adenocarcinoma after First-Line Treatment Failure: A Single-Arm, Single-Center Retrospective Study.

Background: In this study, the clinical efficacy and safety of apatinib combined with irinotecan in HER2-negative patients with first-line treatment failure for advanced gastric adenocarcinoma and gastroesophageal junction (GEJ) adenocarcinoma were evaluated.

Methods: We performed a single-arm, retrospective study at one tertiary hospital in Guangzhou, China. Eligible patients aged 28-77 years with histologically confirmed HER2-negative advanced gastric cancer who had previously received first-line treatment were included. The patients received irinotecan (180 mg/m² intravenously once every 3 weeks) plus oral apatinib (500 mg once daily on days 1-21 of each 3-week cycle), until disease progression, unacceptable toxicity, or death. The primary endpoints were progression-free survival (PFS) and overall survival (OS), which were calculated via the Kaplan‒Meier method.

Results: Between Feb 21, 2019, and Aug 14, 2023, 79 patients met the inclusion criteria. The median PFS was 3.20 months (95% CI, 1.57‒4.83), and the median OS was 7.60 months (95% CI, 5.11‒10.10). According to RECIST version 1.1, 15 patients (18.99%) achieved an objective response, and 31 patients (39.24%) achieved disease control. In terms of the safety profile, 72.2% of patients experienced treatment-emergent adverse events of any grade, among whom, 59.5% of patients experienced grade 1-2 adverse events and 12.7% of patients experienced grade 3-4 adverse events.

Conclusion: Apatinib combined with irinotecan demonstrates modest efficacy with manageable safety profiles in HER2-negative patients with advanced gastric or GEJ adenocarcinoma for whom first-line treatment has failed. Further prospective studies are warranted.