An Exploratory Analysis Based On Tumor Location Of Reachin, A Randomized Double-Blinded Placebo-Controlled Phase Ii Trial Of Regorafenib After Failure Of Gemcitabine And Platinum-Based Chemotherapy For Locally Advanced (Nonresectable) And Metastatic Biliary Tract Tumors.

e15622 Background: The REACHIN trial met its primary endpoint of improving PFS for patients with biliary tract cancer (BTC) treated with regorafenib (R) as compared to placebo (P): Median (m) PFS for R was 3.0 months (mo) (95% CI: 2.3-4.9) and 1.5 mo (95% CI : 1.2-2.0) for P with an HR= 0.49 (95% CI: 0.29-0.81), p=0.005 (Demols A et al, ASCO-GI 2019, Abstr 345). We exploratory analyzed the benefit of R according to tumor location: intra-hepatic (ICC), extra-hepatic (ECC), gallbladder (GB) or peri-hilar (PH). Methods: Tumor locations were recorded at randomization of patients in REACHIN (NCT02162914), a multicenter double-blinded P-controlled randomized phase II study to evaluate the safety and efficacy of R in patients with locally advanced (non resectable) and metastatic histologically proven BTC, progressing after gemcitabine-platinum. We analyzed mPFS according to tumor location and their respective 95% CI. Results: 66 patients were randomized and the mPFS data are summarized in the table. Conclusions: Most of the patients had ICC location (64%). The mPFS in the P arm is similar according to the tumor location. Despite its exploratory value and the small number of patients per tumor location, R seems superior to P in ICC, GB and PH. Data in ECC are not conclusive. Additional biomarkers (FGFR, NGS analysis) are ongoing and will be presented at the meeting. Clinical trial information: NCT02162914. [Table: see text]