Efficacy and conversion outcome of chemotherapy combined with PD-1 inhibitor for patients with unresectable or recurrent gallbladder carcinoma: a real-world exploratory study

BackgroundGallbladder carcinoma (GBC) is an extremely aggressive tumor of the biliary tract with a bleak prognosis, and the evidence supporting the benefit of available systemic therapy for advanced GBC is scarce. Herein, this study intended to investigate the real-world outcome of chemotherapy combined with programmed death-1 (PD-1) inhibitor for the management of unresectable or recurrent GBC.MethodsFrom January 2018 to December 2023, consecutive patients who were treated with systematic treatment, including chemotherapy or the combination of chemotherapy plus PD-1 inhibitor, for unresectable or recurrent GBC were retrospectively identified. Clinical data regarding baseline characteristics, therapeutic response, adverse events (AEs), and oncological outcomes were collected.ResultsThe eligible patients were allocated to combination therapy arm (n = 46) and mono-chemotherapy arm (n = 19). After propensity score matching (PSM), 16 patients were allocated in each arm. The overall survival (OS) and progression-free survival (PFS) of combination therapy were marginally superior to mono-chemotherapy both before and after PSM. The combination therapy exhibited advantage over mono-chemotherapy in regards to partial response (PR) (before PSM: P = 0.009; after PSM: P = 0.037) and objective response rate (ORR) (before PSM: P = 0.006; after PSM: P = 0.015). In combined therapy cohort, 1 patient achieve a complete response, and 13 patients were assessed as appropriate for surgical excision, among which 1 patient refused further surgical intervention.ConclusionsIn patients with unresectable or recurrent GBC, the combination of chemotherapy and PD-1 inhibitor as first-line therapy exhibited prolonged OS and PFS, and increased PR and ORR over those receiving chemotherapy alone, with an acceptable toxicity profile. The combination therapy may be a potential conversion therapy in unresectable GBC patients.