The feasibility and tolerability of anlotinib plus PD-1 blockades among patients with previously immunotherapy treated advanced esophageal squamous cell carcinoma (ESCC): Update results of a retrospective exploratory study.

e16006 Background: Immunotherapy (ICI) demonstrated promising efficacy for patients with advanced ESCC in both second-line and first-line treatment clinically. Therefore, whether the patients might benefit from the PD-1 blockades-related regimens when they failed after the previous ICI remained to be identified and the feasibility of PD-1 blockades rechallenge in ESCC was warranted to be explored. As a novel oral multi-targeted tyrosine kinase inhibitor (TKI) for tumor angiogenesis and proliferation, anlotinib was an efficacious second-line monotherapy for ESCC in China and the combination of anlotinib plus PD-1 blockades might be a promising strategy for patients with previously ICI treated advanced ESCC. Methods: This multicenter, retrospective study was planned to include 110 patients with previously ICI treated advanced ESCC from 9 hospitals in China who were treated with anlotinib plus PD-1 blockades in clinical practice from July 2018 to November 2022 consecutively. The Outcomes included overall survival (OS), objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and safety. Results: At the date of data-cutoff (May 12 2023), 110 eligible patients were available to be analyzed. Characteristics were as follows: median age of 64 years, male/female 74.5%/25.5%, ECOG PS 0/1/2 22.7%/75.5%/1.8%, clinical stage II/III/IV 0.9%/20.9%/78.2%. All the patients had received ICIs and 10.9% patients were treated with TKIs previously. 39.1% patients had received first-line therapy, 41.8% patients had received second-line, 19.1% patients had received third or above line previously. Prognostic outcomes exhibited that the median OS was 11.1 months (95%CI: 8.6-13.7), 12-month OS rate, 24-month OS rate were 47.6% and 30.8%, separately. Additionally, the median PFS was 5.6 months (95%CI: 4.4-6.8). In 110 patients, ORR was 19.1% (95%CI: 12.2%-27.7%), DCR 69.1% (95%CI: 59.6%-77.6%). Safety profile of anlotinib plus PD-1 blockades indicated that the treatment related adverse events (TRAEs) were 89.1%. The most common TRAEs were anaemia (62.7%), hypothyroidism (25.5%), hypoalbuminemia (21.8%), lymphocytopenia (20%), leukopenia (19.1%). Conclusions: Anlotinib plus PD-1 blockades demonstrated encouraging efficacy and tolerable adverse reactions among patients with advanced ESCC who had received immunotherapy previously and the feasibility of PD-1 blockades rechallenge in ESCC was promising to be elucidated. Clinical trial information: ChiCTR2300070777.