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.