The EvIDHence study: real-world treatment patterns and safety outcomes in mutant and wild-type IDH1 cholangiocarcinoma before availability of mIDH1 inhibitors

Background Treatment options for cholangiocarcinoma (CCA) are limited, with poor overall survival (OS). The impact of molecular alterations on clinical outcomes in real-world practice is poorly understood. Patients and Methods EvIDHence was a retrospective, descriptive, multicenter, international, chart review study investigating the natural disease course of patients with advanced/metastatic CCA who underwent mutant isocitrate dehydrogenase-1 (m IDH1 ) testing and initiated second-line treatment on or before 1 July 2019 until 31 December 2021, before commercial availability of mIDH1-targeted therapy. Outcomes included patient, disease, and treatment characteristics, biomarker testing and survival. Results Sixty-three patients with CCA (31 m IDH1 ; 32 IDH1 wild-type) were included. There were no differences in patient and disease characteristics between m IDH1 and IDH1 wild-type groups. Biomarker testing was carried out in the context of research/clinical trials in 61.9% of patients. The most frequent first- and second-line systemic regimens were gemcitabine plus cisplatin and FOLFOX, respectively. Median OS from first-line treatment initiation was 20.8 [95% confidence interval (CI) 15.1-29.3] and 18.6 (95% CI 13.0-20.5) months for m IDH1 and IDH1 wild-type groups, respectively. Median OS from second-line treatment initiation was 9.7 (95% CI 5.5-11.2) and 8.5 (95% CI 6.5-11.3) months for patients with m IDH1 and IDH1 wild-type CCA, respectively. Conclusion These real-world data highlight the poor prognosis of patients with CCA, regardless of IDH1 mutational status. Limitations included the small sample size and biased selection of patients still fit for second-line therapy.