Project Summary Esophageal cancer has a higher incidence rate in US veterans than the general population, and its prognosis is generally poor with a five-year overall survival rate of less than 20%. While most clinical trials focus on patients with metastatic esophageal cancer, novel therapies added to curative intent chemoradiation and surgery in patients with localized esophageal cancer have the greatest potential to improve overall survival rates. Patients who achieve a pathologic complete response on esophagectomy after chemoradiation have a five-year overall survival rate of 50%. Thus, a worthy goal is to increase the number of patients who achieve a pathologic complete response. Treatment of esophageal cancer cells and xenografts with itraconazole, a commonly used antifungal medication, inhibited cellular proliferation and AKT and Hedgehog signaling, two pathways suspected of mediating chemoradiation resistance. In a completed phase 0 trial, we found that a two-week course of oral itraconazole given before chemoradiation was safely tolerated by patients and successfully inhibited AKT and Hedgehog signaling in tumors. We now propose a single-arm phase II trial in which 78 patients will receive oral itraconazole for an eight-week course between standard of care chemoradiation and esophagectomy. The rationale for administering itraconazole during this period is several fold: 1) if AKT and Hedgehog signaling are upregulated by chemoradiation in esophageal cancer, then more cancer cells would be susceptible to itraconazole after chemoradiation; 2) we can administer itraconazole for a longer duration than in our phase 0 trial; and 3) patients are not actively being treated during the proposed administration time period which provides a window of opportunity. Our primary endpoint will be the pathologic complete response rate as assessed by pathology review at the time of esophagectomy in these 78 patients as compared to 156 contemporary propensity score-matched controls. Secondary endpoints include 1) determining if plasma and esophageal levels of itraconazole and hydroxyitraconazole in all patients and molecular pathway status in residual tumors correlate with treatment response and 2) determining if circulating tumor DNA levels, as measured by Natera's Signatera test, correlate with treatment response. As part of the Signatera test, we will also obtain germline and somatic tumor whole exome sequencing data from each patient. Specific Aim 1 will test the hypothesis that itraconazole will increase the pathologic complete response rate by at least 15% compared to controls. Specific Aim 2 will determine if treatment response correlates with drug and metabolite levels in plasma and esophageal tissue and AKT and Hedgehog pathway status and microvessel density (VEGFR2 pathway status) in residual tumors. Specific Aim 3 will utilize whole exome sequencing of untreated tumors to develop a comprehensive genomic profile that predicts treatment response (pre...