Summary

This phase III trial uses the Decipher risk score to guide therapy selection. Decipher score is based on the activity of 22 genes in prostate tumor and may predict how likely it is for recurrent prostate cancer to spread (metastasize) to other parts of the body. Decipher score in this study is used for patient selection and the two variations of treatment to be studied: intensification for higher Decipher score or de-intensification for low Decipher score. Patients with higher Decipher risk score will be assigned to the part of the study that compares the use of 6 months of the usual treatment (hormone therapy and radiation treatment) to the use of darolutamide plus the usual treatment (intensification). The purpose of this section of the study is to determine whether the additional drug can reduce the chance of cancer coming back and spreading in patients with higher Decipher score. The addition of darolutamide to the usual treatment may better control the cancer and prevent it from spreading. Alternatively, patients with low Decipher risk score will be assigned to the part of the study that compares the use of radiation treatment alone (de-intensification) to the usual approach (6 months of hormone therapy plus radiation). The purpose of this part of the study is to determine if radiation treatment alone is as effective compared to the usual treatment without affecting the chance of tumor coming back in patients with low Decipher score prostate cancer. Radiation therapy uses high energy to kill tumor cells and reduce the tumor size. Hormone therapy drugs such as darolutamide suppress or block the production or action of male hormones that play role in prostate cancer development. Effect of radiation treatment alone in patients with low Decipher score prostate cancer could be the same as the usual approach in stabilizing prostate cancer and preventing it from spreading, while avoiding the side effects associated with hormonal therapy.

Objectives

PRIMARY OBJECTIVES:
I. To determine whether men with National Comprehensive Cancer Network (NCCN) unfavorable intermediate risk (UIR) prostate cancer and lower Decipher genomic risk (Decipher score < 0.40) treated with radiation therapy (RT) alone instead of 6 months androgen deprivation therapy (ADT) + RT experience non-inferior rate of distant metastasis. (De-intensification study)
II. To determine whether men with NCCN UIR prostate cancer who are in the higher genomic risk (Decipher score >= 0.40) will have a superior metastasis-free survival through treatment intensification with darolutamide added to the standard of RT plus 6 months ADT. (Intensification study)

SECONDARY OBJECTIVES:
I. To compare overall survival (OS) between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
II. To compare time to prostate specific antigen (PSA) failure between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
III. To compare metastasis free survival (MFS) based on conventional imaging between the standard of care (RT plus 6 months of ADT) and de-intensification intervention (RT alone).
IV. To compare MFS based on either conventional and/or molecular imaging between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
V. To compare cumulative incidence of locoregional failure based upon conventional imaging and/ or biopsy between standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months ADT plus darolutamide) interventions.
VI. To compare cumulative incidence of distant metastasis based upon conventional imaging between standard of care (RT plus 6 months of ADT) and intensification intervention (RT plus 6 months ADT plus darolutamide).
VII. To compare cumulative incidence of distant metastasis based upon either conventional and/or molecular imaging between standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
VIII. To compare prostate cancer-specific mortality between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
IX. To compare sexual and hormonal related quality of life, as measured by the Expanded Prostate Cancer Index Composite-26 (EPIC), between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
X. To compare fatigue, as measured by the Patient Reported Outcomes Measurement Information System (PROMIS)-Fatigue instrument, between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
XI. To compare cognition, as measured by the Functional Assessment of Chronic Illness Therapy-Cognitive (FACT-Cog) perceived cognitive abilities subscale, between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.

EXPLORATORY OBJECTIVES:
I. To compare changes in cardio-metabolic markers, including body mass index, lipids, blood glucose, complete blood count (CBC), comprehensive metabolic panel (CMP), and hemoglobin (Hgb) A1c, between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
II. To compare PSA failure-free survival with non-castrate testosterone and no additional therapies between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
III. To compare cumulative incidence of locoregional failure based upon either conventional and/or molecular imaging between standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
IV. To compare castrate-resistant prostate cancer (CRPC) between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
V. To compare bowel and urinary function related quality of life, as measured by the Expanded Prostate Cancer Index Composite-26 (EPIC), between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
VI. To compare time to testosterone recovery (defined as a T > 200ng/dL) between the standard of care (RT plus 6 months of ADT) and intensification (RT plus 6 months of ADT plus darolutamide) interventions.
VII. To compare health utilities, as measured by the European Quality of Life Five Dimension Five Level Scale (EQ-5D-5L), between the standard of care (RT plus 6 months of ADT) and either the de-intensification (RT alone) or intensification (RT plus 6 months of ADT plus darolutamide) interventions.
VIII. To develop and assess a machine learning/artificial intelligence algorithm for radiotherapy planning and/or quality assurance.
IX. To perform future translational correlative studies using biological data, Decipher results, and clinical outcomes.

OUTLINE:

DE-INTENSIFICATION STUDY: Patients with Decipher score < 0.40 are randomized to 1 of 2 arms.

ARM I: Patients undergo radiation therapy (RT) using a recognized regimen (2-3 days a week or 5 days a week for 2-11 weeks) in the absence of disease progression or unacceptable toxicity.

ARM II: Patients undergo RT as Arm I. Patients also receive androgen deprivation therapy (ADT) consisting of leuprolide, goserelin, buserelin, histrelin, triptorelin, degarelix, or relugolix at the discretion of the treating physician, for 6 months in the absence of disease progression or unacceptable toxicity. Patients may also receive bicalutamide or flutamide for 0, 30 or 180 days.

INTENSIFICATION STUDY: Patients with Decipher score >= 0.40 are randomized to 1 of 2 arms.

ARM III: Patients receive treatment as in Arm II.

ARM IV: Patients receive RT and ADT as in Arm II. Patients also receive darolutamide orally (PO) twice daily (BID). Treatment repeats every 90 days for up to 2 cycles in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 3, 6, 12, 24, 36, 48 and 60 months.