NCT04247217

Immune Profiling After HDR in Local Relapsed Prostate Cancer

Prostate Cancer Immune Profiling Before, During and After HDR-brachytherapy in Local Relapsed Prostate Cancer (PRIMUS-study)

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 10 (actual)
• Sponsor: Maastricht Radiation Oncology · Academic / Other
• Sex: Male
• Age: 18 Years
• Healthy volunteers: —

Summary

Immunotherapy is currently revolutionizing the field in oncology. However, prostate cancer until now fails to respond to classical IO, like PD-1 and CTLA-4 inhibitors. Radiotherapy (RT) delivered to the primary tumor impacts both tumor cells and surrounding stromal cells. Radiation damage to cancer cells exposes tumor-specific antigens leading to increased visibility to the immune system by improved priming and activation of cytotoxic T cells. RT-induced modulation of the tumor microenvironment may also facilitate the recruitment and infiltration of immune cells by increasing the expression or T-cell attracting chemokines and by increasing T-cell docking molecules on the endothelial cells like VCAM-1. The main-hypothesis is that HDR-brachytherapy will turn an immunologically "cold" (no T-cell infiltrations) prostate cancer into an immunologically "hot" (CD4 and CD8-cell infiltrations) tumor, creating leverage points for different forms of IO.

Detailed description

Prospective analysis of biopsies from 10 patients with local recurrence in the prostate selected for salvage HDR brachytherapy in MAASTRO Clinic, Maastricht. HDR treatment is standard in Maastro Clinic for local relapses of prostate cancer after previously irradiation (internal or external). Biopsies will be taken at 4 different time points (before and after the 1st fraction; before the 2nd and 3rd fraction of the salvage treatment). Several immunotyping (expression of PD-(L)-1, CXCL12, IL-23 receptor, etc.) and HLA class I expression will be performed on the biopsies. In addition, HLA genotypes will be determined on DNA isolated from pheripheral blood. The plasma and the biopsies will be stored for eventually additional research.

Conditions

• Prostate Cancer
• PD-L1

Interventions

Type	Name	Description
RADIATION	HDR salvage brachytherapy	In patients receiving HDR salvage brachytherapy for locally relapsed prostate cancer serial biopsies will be performed at 4 different time points.

Timeline

• Start date: 2020-02-19
• Primary completion: 2021-12-23
• Completion: 2021-12-23
• First posted: 2020-01-29
• Last updated: 2022-05-26

Locations

1 site across 1 country: Netherlands