Long-term follow-up assessment of a HER-2/neu peptide (E75) vaccine for the prevention of recurrence in high-risk prostate cancer patients

3067 Background: E75 is an immunogenic peptide from the HER2/neu protein that is expressed in prostate cancer. High-risk prostate cancer (HRPC) patients demonstrating various levels of HER2/neu expression were vaccinated with E75 peptide + GM-CSF to prevent post-prostatectomy prostate-specific antigen (PSA) and clinical recurrences. Methods: 40 HRPC patients were prospectively identified using the validated Center for Prostate Disease Research (CPDR)/CaPSURE high-risk equation and enrolled. HLA-A2+ patients (n=21) were vaccinated (V), and HLA-A2- patients (n=19) were followed as clinical controls (C). HER2/neu over-expressors (OE) were defined as IHC 3+ and low-expressors (LE) as IHC 0–2+. All patients were assessed for clinico-pathologic factors, PSA recurrence (≥0.2ng/ml), clinical recurrence and survival. Results: Comparing the V and C groups, there were no statistical differences in clinico-pathologic factors; however, the V group had larger tumors (≥T3b-T3c: 35% vs. 18%), higher postop Gleason scores...