Dr. Fong Discusses Immune Response to Sipuleucel-T

Lawrence Fong, MD, associate professor, Department of Medicine (Hematology/Oncology), University of California, San Francisco, explains that not understanding the mechanism of action for the various immunotherapies is one of the greatest challenges facing the field.

In order to gauge the immune response, a trial was conducted that administered the immunotherapy sipuleucel-T (Provenge) prior to prostatectomy. Once the prostate was removed, the trial examined the immune response in the tissue in order to assess the degree of activity. An increase in T cells was observed within the prostate and specifically around the edges of the tumor, Fong notes. Additionally, an immune response was linked directly to the target antigens used by sipuleucel-T.

Fong believes this trial provides further insight into the mechanism of action of immunotherapies. The next step for these trials is to investigate how the T cells affect the tumors and the degree of clinical activity.