Effectiveness and safety of radiotherapy plus programmed death-1 inhibitors and lenvatinib in patients with advanced biliary tract carcinoma: a real-world study

Background Radiotherapy (RT) may function synergistically with immunotherapy and targeted agents (TA). This study aimed to assess the effectiveness and safety of RT combined with programmed death-1 (PD-1) inhibitors and lenvatinib in patients with relapsed or refractory advanced biliary tract carcinoma (BTC). Methods This retrospective study included patients with relapsed or refractory advanced BTC who received RT combined with PD-1 inhibitors and lenvatinib at the Peking Union Medical College Hospital (PUMCH). Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and safety were evaluated. Results Thirty-one patients who received RT combined with PD-1 inhibitors and lenvatinib as a second- or later-line therapy were analyzed. RT sites were mainly distributed in the liver lesions (64.5%) and lymph nodes (58.1%). The ORR and DCR were 32.3% (10/31; 95% CI: 14.8–49.7) and 87.1% (27/31; 95% CI: 74.6–99.6), respectively. The median PFS (mPFS) and median OS (mOS) were 7.9 (95% CI: 7.1–8.7) and 11.7 (95% CI: 8.3–15.0) months, respectively. Subgroup analyses of this cohort included 12 and 19 patients who received concurrent and salvage (> 6 weeks after commencing PD-1 inhibitor therapy) RT, respectively. The salvage RT group had higher mOS (11.7 vs. 10.5; p = 0.75) and mPFS (7.9 vs. 6.9; p = 0.85) than the concurrent RT group; however, statistical significance was not reached. All patients experienced any-grade adverse events (AEs), and excessive PD-1 inhibitors or RT toxicity were not observed. Conclusions RT, PD-1 inhibitors, and lenvatinib may be safely combined and have antitumor effectiveness in patients with advanced BTC.