@mpuap, I found these 2 clinical trials currently underway at Mayo Clinic investigating the use of dendritic cell therapy in cancer.
https://www.mayo.edu/research/clinical-trials/search-results?keyword=Dendritic%20Cell%20therapy&studySiteStatusesGrouped=#0c1d955fe5494ae68c25c6f1aad733c4
Additionally, to inquire about trials in colon or prostate cancer, you can call Mayo Clinic to talk with someone about available clinical trials.

Here's the info:
CANCER-RELATED CLINICAL STUDIES QUESTIONS
https://www.mayo.edu/research/clinical-trials
Phone: 855-776-0015 (toll-free)
Contact form https://www.mayo.edu/research/forms/cancer-clinical-trials