A retrospective analysis of efficacy and safety of lenvatinib combined with PD-1 inhibitor and chemotherapy in advanced biliary tract cancer (BTC).

e16173 Background: Lenvatinib combined with PD-1 inhibitor and chemotherapy has showed a relatively high antitumor activity for ICC in phase 2 clinical trials. This study retrospectively analyzes the efficacy and safety of real-world lenvatinib combined with PD-1 inhibitor and chemotherapy in BTC. Methods: Patients with advanced BTC who received lenvatinib combined with PD-1 inhibitor plus oxaliplatin and gemcitabine (Gemox) chemotherapy were retrospectively screened. The overall survival, progression-free survival, objective response rate, disease control rate and safety were evaluated. Results: From Jan 2021 to Apr 2023, 27 pathologically-confirmed advanced BTC pts were enrolled. The median age is 61 (range, 39-74) years, 18 (66.7%) were male. Fourteen patients had TNM stage Ⅳdisease, and 7 patients had stage III. Twenty-six (96.3%) patients had an ECOG performance status of 1. All patients were child-pugh A. Fourteen patients had metastasis, 8 patients with lymph node metastasis, 4 with bone metastasis. 11 (40.7%) had positive PD-L1 expression. At baseline, 18 (66.7%) patients had a CA19-9 level > 200 U/mL. The median CEA level was 3.56 ng/mL; 48.1% of the patients had a level > 5 ng/mL. At the date cut off (Dec 15, 2023), the median follow-up time was 10.4 months (range: 4.8-25.7). ORR was 70.4% (19/27), and disease control rate (DCR) was 85.2% (23/27). Three pts with locally advanced disease were down-staged and then underwent resection. They remained disease-free survival at the end of last follow-up. The median PFS was 9.0 months (95% CI: 4.0-14.0) and median duration of response (DOR) was 9.8 months. The median OS was 20.4 months (95% CI: 13.6-27.2). 12-months OS rate was 73.3% (95% CI: 57.5%-89.2%).20/27 pts experienced treatment-related adverse events (AE). No grade 5 AE was observed. The most common AE was fatigue 66.7% (18/27), headache 7.4% (2/27). Grade 3 fatigue and grade 3 kidney injury occurred in 1 patient separately. Conclusions: Lenvatinib combined with PD-1 inhibitor and Gemox chemotherapy provided remarkable efficacy with reasonable tolerability in advanced BTC patients.