Efficacy and safety of anlotinib plus programmed death-1 blockade versus anlotinib monotherapy as second or further-line treatment in advanced esophageal squamous cell carcinoma: A retrospective study

BackgroundBoth anlotinib and programmed death-1 (PD-1) blockade have been approved for the second-line treatment of metastatic esophageal squamous cell carcinoma (ESCC). However, the combination of these two therapies has not been evaluated. This study investigated the efficacy and safety of anlotinib, a novel multitarget tyrosine kinase inhibitor targeting tumor angiogenesis, combined with PD-1 blockade as second or further-line treatment for advanced ESCC. MethodsBetween January 2019 and February 2021, 98 advanced ESCC patients receiving anlotinib plus PD-1 blockade or anlotinib monotherapy as second or further-line treatment at Henan Cancer Hospital were retrospectively analyzed. Patients receiving anlotinib plus PD-1 blockade were grouped as cohort A (n=48), while those receiving anlotinib monotherapy were grouped as cohort B (n=50). The primary endpoint was progression-free survival (PFS). Secondary endpoints included the objective response rate (ORR), disease control rate (DCR) and toxicity. Furthermore, independent prognostic factors were identified by Cox regression analysis. A two-sided p-value of