Description

Biliary tract cancers (BTCs) have a higher prevalence in Asia compared to Western countries, with South Korea ranking second globally in BTC incidence. According to data from the Central Cancer Registry in 2023, the 5-year survival rate for BTC from 2017 to 2021 was 28.9%, significantly lower than other cancers such as gastric cancer (77.9%), colorectal cancer (74.3%), and breast cancer (93.8%).

Surgery is the primary treatment for BTC, but only 40-50% of patients are eligible for curative resection. For patients with unresectable, advanced, or metastatic BTC, the standard first-line treatment has been gemcitabine plus cisplatin (GP) since the results of the ABC-02 Phase 3 trial in 2010. Recently, two Phase 3 trials-TOPAZ-1 in 2022 and KEYNOTE-966 in 2023-demonstrated significant survival benefits with the addition of immune checkpoint inhibitors (durvalumab or pembrolizumab) to GP therapy, establishing these combination regimens as the new first-line standard treatment for advanced BTC. These combinations have been approved for use in South Korea.

However, for patients who fail first-line GP therapy, the most commonly selected second-line treatment, FOLFOX (5-FU + leucovorin + oxaliplatin), offers only a modest survival extension of about one month compared to supportive care. This highlights the clinical unmet need for more effective second-line treatments. A multicenter Phase 2 trial has demonstrated the efficacy of lenvatinib plus pembrolizumab as a promising treatment option for these patients.

This prospective observational study aims to evaluate the clinical efficacy and safety of lenvatinib plus pembrolizumab combination therapy in real-world clinical practice for advanced BTC. Additionally, the study seeks to explore potential predictive biomarkers through genetic analyses of blood and tissue samples to better understand which patients are most likely to benefit from this treatment.