Adjuvant tislelizumab, lenvatinib, and capecitabine for resected biliary tract cancer: a prospective phase II trial.
BACKGROUND: This study aims to assess the efficacy and safety of a triplet adjuvant regimen consisting of tislelizumab, lenvatinib, and capecitabine following radical resection in patients with biliary tract cancer (BTC). METHODS: In this open-label, single-arm trial, patients with histologically confirmed BTC who had undergone curative resection were enrolled to receive adjuvant therapy within 4-16 weeks postoperatively. The treatment regimen consisted of tislelizumab (200 mg), lenvatinib (8 mg), and capecitabine (1250 mg/m2). The primary endpoint was the 1-year disease-free survival (DFS) rate. Secondary endpoints included median DFS, 2-year DFS rate, and 1- and 3-year overall survival (OS) rates, as well as safety profiles. Exploratory analyses were conducted to evaluate genomic alterations and prognostic biomarkers associated with clinical outcomes. RESULTS: Between February 24 and December 31, 2022, a total of 50 patients underwent treatment. As of the data cutoff (April 30, 2025), the median follow-up duration was 29.3 months (95% CI: 27.2-30.4). Intrahepatic cholangiocarcinoma constituted 78% of cases, with TNM stage III or IV observed in 40% of patients and poorly differentiated tumors identified in another 40%. The median DFS was calculated at 12.7 months (95% CI: 6.4-19.0), with DFS rates being reported as 55.5% (95% CI: 51.4%-57.6%) at 1 year and 30.8% (95% CI: 28.6%-32.9%) at 2 years, respectively. Median OS was not reached; however, the 1-year OS rate stood at an impressive figure of 93.8% (95% CI: 91.7%-95.9%) while the 3-year OS rate declined to 54.4% (95% CI: 50.0%-58.4%). By the exploratory analyses, FSIP2 mutation was associated shorter DFS (P < 0.001). Treatment-related grade 3 adverse events occurred in 20% of patients, with no treatment-related deaths or grade ≥ 4 toxicities reported. CONCLUSIONS: Adjuvant tislelizumab, lenvatinib, and capecitabine demonstrated clinical activity and tolerable safety in patients with resected BTC. Despite not meeting the primary endpoint, continued follow-up and further evaluation are warranted to better define the potential role of this combination regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05254847; registered prospectively on February 15, 2022.