A phase I pilot study of autologous heat shock protein vaccine HSPPC-96 in patients with resected pancreatic adenocarcinoma

We performed a phase I pilot study to determine if autologous vaccine HSPPC-96 (gp96, Oncophage (R)) could be purified from completely resected pancreas adenocarcinomas, to determine patient tolerance of vaccine and to explore immune responses and clinical outcomes of these patients. Subjects were vaccinated with 5 mu g of autologous HSPPC-96 weekly for 4 doses. Serial ELISPOT assays of T cells for antitumor reactivity were performed. Subjects received neither adjuvant chemotherapy nor radiation. Ten patients received a full course of vaccinations. No dose-limiting toxicities were encountered. Immediate freezing in liquid nitrogen of the tumor specimen resulted in improved vaccine yield. Median overall survival is 2.2 years (Kaplan-Meier estimate). Autologous anti-HSPPC-96 ELISPOT reactivity increased significantly in 1 of 5 patients examined and a second had an increase of unclear significance. Three of 10 treated patients are alive without disease at 2.6, 2.7, and 5.0 years follow-up. There was no observed correlation between immune response and prognosis. This study demonstrates the feasibility of preparing HSPPC-96 from pancreatic adenocarcinomas. Examination of this novel approach using multiple dose levels is 1 approach to further investigate the immunogenicity and clinical utility of HSPPC-96 vaccination in this setting.