Novel PAP-derived vaccine for the treatment of advanced prostate cancer

Abstract

Background: Treatment options for patients with advanced prostate cancer (PC) still remain limited and rarely curative. The prostatic acid phosphatase (PAP) is prostate specific protein over-expressed in more than 90% of prostate tumours. Although an FDA-approved vaccine for the treatment of advanced prostate disease, PROVENGE® (sipuleucel-T), has been shown to prolong survival, the precise sequence of the PAP protein responsible for the outcome remains unknown. The aim of the study is to develop a cheaper and more effective, Prostatic Acid Phosphatase (PAP)-based, vaccine for the treatment of advanced prostate cancer. Our laboratory has previously shown that a 15mer PAP-derived vaccine, when injected as a DNA vaccine, could induce PAP-specific T-cell responses and reduce tumor growth in a syngeneic heterotopic murine prostate cancer model. We have subsequently developed an elongated (42mer) PAP-derived peptide containing Leucine instead of an Alanine at position 14.