This phase II trial tests how well relugolix and enzalutamide, in combination with radiation therapy, works in treating patients with very high risk prostate cancer. Relugolix is a form of androgen deprivation therapy. It prevents the release of testosterone, a hormone required to sustain prostate growth. Reducing testosterone levels may inhibit the proliferation of prostate tumor cells that need testosterone to grow. Enzalutamide is an androgen receptor signaling inhibitor. It inhibits the activity of prostate tumor cell receptors, which may reduce proliferation of prostate tumor cells. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Adding relugolix and enzalutamide to radiation therapy may be more effective at treating patients with very high risk prostate cancer than giving any of these treatments alone.
cT3b-cT4 (American Joint Committee on Cancer [AJCC] 9.0)
> 4 cores with grade group 4 or 5 prostate cancer
Primary gleason pattern 5
2 or 3 NCCN high-risk features.
Patients with definitive clinical or radiologic evidence of metastatic disease
Patients with prior invasive malignancy (except non-melanomatous skin cancer carcinoma in situ of the male breast, penis, oral cavity, or stage Ta of the bladder, or stage I completely resected melanoma) unless disease free for a minimum of 2 years
Prior radiotherapy that would result in overlap of radiation therapy fields
History of documented inflammatory bowel disease
Single group
Biopsy
Procedure/SurgeryUndergo biopsy
Biospecimen Collection
Procedure/SurgeryUndergo collection of blood samples
Computed Tomography
Procedure/SurgeryUndergo CT
Enzalutamide
DrugGiven PO
Fluorine F 18 Piflufolastat
Other interventionUndergo fluorine F 18 piflufolastat PET/MRI
Image Guided Radiation Therapy
RadiationUndergo IGRT
Magnetic Resonance Imaging
Procedure/SurgeryUndergo PET/MRI
Positron Emission Tomography
Procedure/SurgeryUndergo PET/MRI
Questionnaire Administration
Other interventionAncillary studies
Relugolix
DrugGiven PO
Pathologic response (biopsy positivity rate)
Will determine the efficacy of radiation therapy with relugolix and enzalutamide, for a total duration of 18 months, in patients with National Comprehensive Cancer Network very high-risk prostate cancer, by a 2-year biopsy positivity rate.
Disease-free survival
Will be determined by biochemical failure of prostate specific antigen nadir + 2ng/mL, local or regional recurrence, distant metastasis, or death. Median survival time will be estimated with corresponding 95% confidence intervals.
Testosterone recovery
Testosterone recovery will be defined as a total serum testosterone of ≥ 200 ng/dL.
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Sean Sachdev
Lead sponsor
Northwestern University
Sponsor institution
National Cancer Institute (NCI)
Collaborator
