Factors associated with reaching maintenance therapy in patients with advanced biliary tract cancer treated with durvalumab: Real‐world results from a multicenter and multinational study

Standard of care first-line systemic treatment for advanced biliary tract cancer includes chemo-immunotherapy with gemcitabine, cisplatin, and durvalumab, followed by maintenance durvalumab monotherapy. The present work aims to investigate the differences in baseline clinical and molecular characteristics between patients with early progression during chemo-immunotherapy and those who reach durvalumab maintenance therapy. The study population included patients with unresectable, locally advanced, or metastatic BTC who received treatment at 38 clinical Institutions in 12 countries from July 2021 to December 2023. The primary objective of the study was to investigate whether baseline clinical and molecular characteristics differed between patients with early progression during chemo-immunotherapy versus those reaching durvalumab maintenance therapy. Four hundred forty-eight patients were included in this study. Two hundred twenty-seven patients (50.7%) received maintenance with durvalumab monotherapy, whereas 221 (49.3%) did not receive maintenance therapy due to PD during first-line chemo-immunotherapy before completing 8 cycles. Results show that patients who received maintenance were more likely to be older (≥70 years), have an ECOG = 0, locally advanced disease, and a neutrophil-to-lymphocyte ratio (NLR) <3. A higher proportion of patients with BAP1 mutations received maintenance, while TP53 mutations were more common in those who progressed early. According to the present analysis, a substantial proportion of patients (50.7%) with advanced BTC who were treated with chemotherapy plus durvalumab proceeded to receive maintenance therapy with durvalumab monotherapy, with a median treatment duration of 4.4 cycles. Patients ≥70 years, with ECOG PS 0, with locally advanced disease, and with NLR <3 had a higher likelihood of receiving maintenance therapy.