Analysis of PSA-Specific T-Cell Responses of Prostate Cancer Patients Given a PSA-Based Vaccine on a Clinical Trial
Abstract
Cancer vaccines may improve outcomes by inducing an immune response to tumor antigens. This randomized, phase II clinical trial was designed to determine if a PSA-based vaccine could induce a specific immune response when combined with radiotherapy in patients with localized prostate cancer. The primary endpoint is to identify any immunological response to PSA by monitoring T-cell frequencies using the ELISPOT assay. 29 patients have been randomized into vaccine or no vaccine arms both receive standard radiotherapy. The vaccine patients receive recombinant vaccinia PSA and B7.l followed by monthly boosters with fowlpox PSA, as well as GM-CSF and IL-2. No unexpected or severe toxicities have been seen. 11 patients in the vaccine arm have been tested via ELISPOT. 6 showed at least a 3 fold increase in PSA-specific T-cells. None of the 6 tested in the no vaccine arm had an increase. The number of circulating PSA-specific T-cells temporarily decreased following radiotherapy, then returned within 2 months. This may indicate specific cellular trafficking to the prostate. Overall, the PSA-vaccine appears to be well-tolerated and able to produce substantial immune responses, as determined by the ELISPOT assay. It can be safely and, in terms of immune response, effectively combined with local radiotherapy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2003
- Accession Number
- ADA428064
Entities
People
- James L. Gulley
- Jeffrey Schlom
- Kwong Tsang
- Philip M. Arlen
- William Dahut
Organizations
- National Cancer Institute