Clinical Trial: A Phase I Feasibility Study of an Intraprostatic PSA-Based Vaccine in Men With Prostate Cancer With Local Failure Following Radiotherapy or Cryotherapy or Clinical Progression on Androgen Deprivation Therapy in the Absence of Local Definitive Therapy
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: A Phase I Feasibility Study of an Intraprostatic PSA-Based Vaccine in Men With Prostate Cancer and Local Failure Following Radiotherapy or Cryotherapy or Clinical Progression on Androgen Deprivation T
Brief Summary:
Background:
- Pox viral vectors can induce a PSA-specific T-cell responses and clinical responses in patients with advanced prostate cancer.
- Intratumoral vaccines of recombinant fowlpox vectors appear to be more potent in inducing antitumor effects than the s.c. route of administration, especially when the recombinant rF-vector given intratumorally is preceded by a rV-recombinant given s.c. This may be due to:
- Making the tumor cell an antigen presenting cell via upregulation of both antigen (signal 1) and costimulatory molecules (signal 2).
- Making the tumor cell more susceptible to killing via upregulation of ICAM.
- The increased expression of perforin in peptide-specific T cells that came into contact with the TRICOM-infected targets.
- Potentially allowing the immune system to select for other tumor encoded antigens to generate a polyvalent immune response.
Objectives:
- 1: Safety and feasibility of an intraprostatic vaccine strategy.
- 2: To assess the change in PSA-specific T-cell response as measured by ELISPOT assay.
- 2: To evaluate T-cell infiltration histologically in patients who have pre- and post-vaccine prostate biopsies.
Eligibility:
- Must have either a) biopsy proven, locally recurrent prostate cancer following local radiation as defined by the ASTRO consensus criteria as 3 consecutively rising PSA levels or b) have refused
