Clinical Evidence on Apatinib in Treating Chemotherapy-Refractory Metastatic Esophageal Squamous Cell Carcinoma

Majority Chinese esophageal cancer patients have squamous cell carcinoma (ESCC) and with metastasis at initial diagnosis. Treatment for metastatic ESCC where first-line chemotherapy failed is an unmet medical need. Targeting human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor receptor 2 (KDR) have been approved to be effective for esophageal adenocarcinoma (EAC). We explored the clinical relevance of these molecular signaling in ESCC cohorts and collected clinical evidence on applying apatinib, a Chinese FDA-approved KDR inhibitor for late-stage gastric carcinoma, in 26 patients with chemotherapy-refractory metastatic ESCC. The clinical response rate and disease control rate of these patients to apatinib 500mg once daily regimen was 12% and 60%, respectively. The patients’ median progression-free survival time (PFS) was 3.2 months (95% CI, 2.23-4.17 months) and overall survival time (OS) was 5.3 months (95% CI, 4.46-6.14 months). The most common grade 3-4 treatment-related adverse events included leukopenia (7.7%) and anemia (7.7%). No drug-related death occurred. In conclusion, apatinib has favorable activity and acceptable safety, and could be a new treatment option for patients with chemotherapy refractory metastatic ESCC.