A team of University of Iowa Health Care researchers has launched an important clinical trial of a novel therapeutic that may eventually lead to new treatments for men diagnosed with prostate cancer.

The Ad5-TRAIL gene therapy for prostate cancer research trial is a Phase I study designed to test the optimal dosage at which the therapeutic agent can safely be given to patients.

The clinical study is being co-led by Thomas Griffith, Ph.D., an associate professor in the UI Department of Urology, and Richard Williams, M.D., the Rubin H. Flocks Chair in Urology and professor and head of the UI Department of Urology.

“This is the first use of this type of anti-cancer agent which was developed at the University of Iowa. This new gene therapy may help us successfully manage patients with high-risk prostate cancer,” Griffith said. “Ideally, we hope to be able to say at the conclusion of this trial that this novel agent is safe and performs as intended by causing the death of prostate tumor cells with no harm to normal cells. However, being at the initial stages of the trial, it is premature to make any claims until the data is analyzed.”

Researchers injected the investigational therapeutic into the cancerous prostates of three patients. Then, following a 10-day waiting period, surgeons removed the prostates and are evaluating the results.

“The preliminary results appear promising,” Williams said. “The patients have tolerated the treatment without any serious side effects, which we hope will permit us to proceed with the research process.”

Investigators plan to enroll up to 12 additional participants in the Phase I segment of the study.

“While the vaccine is not intended to be curative at this stage, the role of the research participants is critically important to what is truly a team effort. Without the involvement of our patients, we could not succeed,” said Timothy Ratliff, Ph.D., the Anderson-Hebbeln Professor of Urology, and co-investigator in the study.

Funding for this trial has come from the following sources or agencies:

- Roy J. Carver Charitable Trust – funds for preparing the clinical-grade virus;
- Alliance for Cancer Gene Therapy – preclinical studies;
- Holden Comprehensive Cancer Center at the UI – preclinical studies and protocol development;
- U.S. Department of Defense – protocol development and clinical trial;
- National Institutes of Health – clinical trial and Gelfoam studies.

To create the vaccine, the team used a virus that causes the common cold, but which has been engineered to be non-replicative in humans. The disabled virus, known as an adenovirus, can then be used as a vector, or carrier, of other genes that researchers insert into the virus.

The UI researchers say it will take several years before the treatment could be approved and come into general use, even if it is shown to be effective.