Feasibility and Safety of Anlotinib Monotherapy for Patients with Previously Treated Advanced Esophageal Squamous Cell Carcinoma: A Real-World Exploratory Study

OBJECTIVE: This study was to investigate the feasibility and safety of anlotinib monotherapy for patients with advanced or metastatic esophageal squamous cell carcinoma (ESCC) retrospectively. METHODS: This study was designed as a real-world study. A total of 83 patients with advanced or metastatic ESCC who received anlotinib monotherapy were included. Demographic characteristics of the patients, efficacy data of the treatment and adverse reactions during the treatment were documented and analyzed through the electronic medical record system in the hospital. All the patients were followed up regularly. The primary endpoint of this study was progression-free survival (PFS), secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), safety profile and PFS analysis according to adverse reactions. RESULTS: A total of 83 patients with ESCC who received anlotinib monotherapy were included. Partial response was observed in 7 patients, stable disease was noted in 51 patients and progressive disease was found in 25 patients, which yielded an ORR of 8.4% (95% CI: 3.5–16.6%), and a DCR of 69.9% (95% CI: 58.8–79.5%). Furthermore, the median PFS of the 83 patients with advanced ESCC was 3.3 months (95% CI: 2.20–4.40) and the median OS was 7.8 months (95% CI: 5.40–10.20). Common adverse reactions among the 83 patients were hypertension (51.8%), fatigue (48.2%), weight loss (41.0%), diarrhea (34.9) and hand-foot syndrome (30.1%). Correlation analysis between hypertension status and PFS suggested that PFS of the patients with hypertension was longer than that of those with non-hypertension (median PFS: 4.5 vs 3.0 months, P = 0.019). CONCLUSION: Anlotinib monotherapy demonstrated promising efficacy and tolerable toxicity for patients with previously treated advanced or metastatic ESCC. Hypertension that occurs during anlotinib administration might be used as a potential biomarker to predict PFS of patients with ESCC. The conclusion should be confirmed in prospective clinical trials subsequently.