Landscape of clinical trials and impact of precision medicine in biliary tract cancers in the last 45 years: a systematic review and meta-analysis of biomarker-driven trials.

BACKGROUND

Biliary tract cancers (BTCs) collectively are challenging tumors despite some advances in research in the last years. Although multiple efforts, challenges in clinical trial recruitment and positive outcomes persist. With the aim of understanding this landscape of clinical trials, a thorough analysis of clinical trials over the past 45 years was developed.

METHODS

A systematic search of Embase, PubMed, Scopus, and Web of Science was carried out, to identify prospective trials evaluating any intervention in patients with BTCs. Trials were included if they reported specific patient data for BTC. Data regarding epidemiological aspects and outcomes of all trials were extracted. A meta-analysis of randomized trials was performed to compare the efficacy of precision medicine over cytotoxic chemotherapy.

RESULTS

Among 427 trials involving 23,024 patients, 10.8% were phase I, 66% phase II, and 23.1% randomized or multicohort studies. Cholangiocarcinoma (CCA) was the focus in 85 trials (19.9%) while 22 trials (5.15%) didn't clearly report the BTC subtype. Median age was 63 years [interquartile range (IQR): 60-65 years], consistent across the study period. Race was explicitly reported in only 82 trials (19.2%), with 80% of patients identified as White and less than 5% as Black. From 2021 onwards, Asia has become the leading recruitment region. The amount of biomarker-based trials and immunotherapy trials more than doubled between the period 2020-2023. Among randomized first-line trials for advanced disease, sample sizes have increased over time, but median overall survival (OS) has remained approximately 12 months, despite the addition of cytotoxic agents or immunotherapy. In refractory settings, biomarker-driven trials doubled response rates compared to standard approaches [odds ratio (OR) =2.16].

CONCLUSIONS

Over the past 45 years, BTC trials have resulted in modest incremental survival. However, immunotherapy and precision medicine may change this paradigm, justifying the expansion of biomarker-driven approaches in earlier treatment settings. Limitations in patient diversity, reporting standards, and regional representation persist. Future efforts should focus on improving inclusivity and methodological consistency in BTC trials.