A phase 2 trial testing an epigenetic strategy to prime bile duct cancer for immune checkpoint therapy did not generate the intended clinical benefit, according to the study’s report of outcomes alongside detailed immune profiling. The results leave the combination as a negative signal, but the immune data collected during the trial may help guide next-generation biomarker work. The trial examined whether modifying epigenetic regulation could convert tumors that otherwise fail to respond into a more immunologically permissive state. While the clinical response rate did not improve versus expectations for efficacy, the dataset includes information on immune cell populations and activation markers that may point to mechanisms of resistance. For biotech product developers, the read-through is clear: epigenetic-immune combinations remain an active area, but translating “priming” biology into measurable patient benefit continues to be difficult in biliary tract cancers.