Updated results of anlotinib combined with TQB2450 (PD-L1 blockade) as first-line treatment for advanced esophageal squamous cell carcinoma (ESCC): A single-arm, multicenter, open-label phase Ⅱ clinical trial.

4041 Background: PD-1 blockades combined with chemotherapy in first-line setting exhibited encouraging efficacy for patients with ESCC recently. However, the safety profile of conventional chemotherapy was still disappointing. Therefore, the chemotherapy-free regimen might be a promising strategy. As a novel multitarget TKI mainly targeting VEGFR1-3, anlotinib was a potential first-line combination therapy and second-line monotherapy for patients with ESCC in China. TQB2450 was a novel PD-L1 blockade developed by Chia Tai Tianqing Pharmaceutical Group Co., Ltd. (Nanjing, China). Therefore, this study was designed to explore the efficacy and safety of anlotinib combined with TQB2450 as first-line therapy in advanced ESCC. The preliminary results were reported in 2023 ASCO-GI Symposium (Abs 377) and the update results were reported here. Methods: Patients with previously untreated metastatic or locally advanced ESCC, whose age was between 18 and 75 years, with ECOG PS of 0 or 1 and life expectancy of > 3 months were eligible as the inclusion criteria. Eligible patients were administered with anlotinib (12mg, po, d1~14, q3w) plus TQB2450 (1200mg, iv, d1, q3w) until disease progression or unacceptable toxicity. The tumor response was assessed according to RECIST 1.1 and iRECIST using CT scans every 2 cycles for the first 6 cycles, and every 3 cycles thereafter. Adverse events were recorded by severity in accordance with the NCI CTC AE Version 5.0. The predefined sample size was 46. The primary endpoint was ORR. Secondary endpoints included safety, PFS, DCR, DoR and OS. Results: From Mar 2022 to Sep 2022, a total of 46 patients were enrolled. At the data cut-off date (Dec, 2022), there were 1 CR (2.2%), 27 PR (58.7%), 14 SD (30.4%) and 4 NE (8.7%). Therefore, the preliminary ORR was 60.9% (95%CI: 45.4%~74.9%), DCR was 91.3% (95%CI: 79.2%~97.6%). The median PFS of the 46 pts was not yet available. Additionally, safety profile exhibited that the regimen was tolerable. The most common treatment-related adverse events in 46 patients with the incidence > 10% were hypertension (28%), hypothyroidism (20%), leukocytosis (20%), hyperthyroidism (17%), anemia (15%), fatigue (15%), neutrophil count decreased (11%), constipation (11%), sinus bradycardia (11%) and hand-foot syndrome (11%). The common grade ≥3 treatment-related adverse events were hypertension (4%), hand-foot syndrome (2%), hyponatremia (2%), platelet count decreased (2%) and lymphocyte count decreased (2%). Conclusions: Preliminary results suggested that anlotinib combined with TQB2450 as first-line therapy in advanced ESCC exhibited encouraging efficacy and manageable adverse events. And the conclusions needed to be confirmed in trials continued subsequently. Clinical trial information: NCT05038813 .