Safety and Biologic Response of Pre-operative Autophagy Inhibition in Combination with Gemcitabine in Patients with Pancreatic Adenocarcinoma

Autophagy is a cell survival mechanism that plays a critical role in pancreatic carcinogenesis. Murine studies have previously demonstrated that treatment with the late-autophagy inhibitor chloroquine in combination with chemotherapy limited tumor growth. In this phase 1/2 trial, we examined treatment with hydroxychloroquine (HCQ) and gemcitabine for patients with pancreatic adenocarcinoma. The primary endpoints were safety and tolerability, evaluated by Storer's dose escalation design. Secondary endpoints were CA 19-9 biomarker response, R0 resection rates, survival, and correlative studies of autophagy. Thirty-five patients were enrolled. There were no dose-limiting toxicities and no grade 4/5 events related to treatment. Nineteen patients (61 %) had a decrease in CA 19-9 after treatment. Twenty-nine patients (94 %) underwent surgical resection as scheduled, with a 77 % R0 resection rate. Median overall survival was 34.8 months (95 % confidence interval, 11.57 to not reached). Patients who had more than a 51 % increase in the autophagy marker LC3-II in circulating peripheral blood mononuclear cells had improvement in disease-free survival (15.03 vs. 6.9 months, p < 0.05) and overall survival (34.83 vs. 10.83 months, p < 0.05). No outcome differences were demonstrated in the 81 % of patients with abnormal p53 expression assessed by immunohistochemistry in the resected specimens. Preoperative autophagy inhibition with HCQ plus gemcitabine is safe and well tolerated. Surrogate biomarker responses (CA 19-9) and surgical oncologic outcomes were encouraging. p53 status was not associated with adverse outcomes.