53Treatment outcomes of patients with mIDH1 cholangiocarcinoma in the United States
Rachna T Shroff, Lorenza Rimassa, Juan W Valle, Valerie Gunchick, Hakam Gharbi, Renata Robert, Vaibhav SahaiAbstract
Background
Cholangiocarcinoma (CCA) is usually diagnosed at an advanced stage; 10–15% of these patients (pts), mostly with intrahepatic CCA, harbor an IDH1 mutation (mIDH1). Real-world outcome and treatment pattern data are limited; this study aims to further understand the management of patients with mIDH1 CCA.
Methods
This retrospective study utilized Citizen Health real-world data harmonized across 3,000 healthcare institutions in the United States to evaluate pt characteristics, biomarker testing, and treatment patterns. Pts were followed from the date of pathologic or clinical diagnosis until death or censored at the last activity. Descriptive analyses and Kaplan-Meier (KM) for time-to-event endpoints were performed.
Results
602 pts with CCA diagnosed from 2007 to 2025, mostly with advanced or metastatic stage (59.8%), and ECOG performance status 0-1 (65.3%) were included. Majority of pts (n = 499, 82.9%) underwent biomarker testing using tissue (395, 79.2%) or blood (106, 21.2%). Analytic methods included next-generation sequencing (275, 55.1%) and immunohistochemistry (194, 38.9%). Among 499 pts with biomarker testing, 88 pts (18.6%) had mIDH1 CCA. Of them, 80 pts (90.9%) received first-line (1L) systemic therapy for any stage, including gemcitabine-cisplatin (GemCis) (26, 32.5%) or GemCis-durvalumab (21, 26.3%). In the 1L, median progression-free survival (mPFS) was 8.0 months (mo) and median overall survival (mOS) was 30.0 mo. 63 pts (71.6%) received second-line (2L) therapy, including ivosidenib alone (22, 34.9%) or in combination (7, 11.1%). In these 29 pts who received ivosidenib, mPFS was 6.1 mo and mOS was 25.1 mo, while in 34 pts who received other regimens, mPFS was 4.1 mo and mOS was 20.1 mo.
Conclusions
These data show that the majority of pts had access to biomarker testing in real-world practice for CCA. Patients who received ivosidenib as 2L treatment for any stage of IDH1-mutated CCA lived longer than patients who received other 2L regimens. Further studies evaluating causality are required.