<p>The study was a single-center, open-label, phase II trial (registration no. <a href="https://clinicaltrials.gov/study/NCT03250273">NCT03250273</a>) designed to evaluate the efficacy of entinostat in combination with nivolumab in patients with advanced pancreatic ductal adenocarcinoma (PDAC). The aim was to assess the objective response rate using RECIST v1.1 criteria as the primary endpoint. A total of 27 patients with advanced PDA were enrolled from November 2017 to November 2020. Their treatment involved a 14-day lead-in with entinostat monotherapy, followed by a combination with nivolumab. The study utilized several molecular technologies to assess immune profiles and tumor microenvironment (TME) changes: high-dimensional mass cytometry by time of flight (CyTOF), Luminex for chemokine analysis in plasma, multiplexed immunohistochemistry (mIHC), image cytometry-based quantification, bulk RNA sequencing analysis. The objective response rate (ORR) was 11% with three patients showing a partial response (PR). The median duration of response was 10.2 months. Grade ≥ 3 treatment-related adverse events (TRAEs) occurred in 63% of patients, with the most common being decreased lymphocyte count, anemia, hypoalbuminemia, and hyponatremia. Gene expression analysis showed an enrichment in inflammatory response signaling pathways with the combination treatment. RNA sequencing data with clinical and demographic patient information will be available through dbGaP. For expression summaries, please refer to GEO submission <a href="https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE248014">GSE248014</a>.<br></p>

Phase 2 Study of Nivolumab and Entinostat in Unresectable or Metastatic Cholangiocarcinoma and Pancreatic Adenocarcinoma