A Phase 2 interventional study of Apalutamide and Biospecimen Collection in Prostate Adenocarcinoma, Stage II Prostate Cancer AJCC v8 and Stage IIIA Prostate Cancer AJCC v8, sponsored by Jonsson Comprehensive Cancer Center. Recruiting at 1 site in United States. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-17.
Sponsored by Jonsson Comprehensive Cancer Center · Phase 2, Interventional, and Treatment
This phase II trial evaluates apalutamide in combination with image-guided stereotactic body radiation therapy (SBRT) for the treatment of patients with prostate cancer. Prostate cancer usually needs the hormone testosterone to grow. Apalutamide is a hormone therapy that blocks the effect of testosterone on prostate tumor cells. This may help stop the growth of tumor cells that need testosterone to grow. Image-guided SBRT is a standard treatment for some types of prostate cancer. This treatment combines imaging of cancer within the body, with the delivery of therapeutic radiation doses produced on a linear accelerator machine. SBRT uses special equipment to position a patient and deliver radiation to tumors with high precision. This method may kill tumor cells with fewer doses over a shorter period and cause less damage to normal tissue. Combining apalutamide with image-guided SBRT may increase a prostate cancer patient's chances of achieving an extremely low prostate specific antigen response, which is an early predictor of disease cure.
PRIMARY OBJECTIVE:
I. To assess prostate specific antigen (PSA) complete response rates in patients with unfavorable intermediate risk prostate cancer who are receiving apalutamide monotherapy in conjunction with magnetic resonance imaging stereotactic body radiotherapy with precision dose-escalation and de-escalation to involved and uninvolved areas of the prostate, respectively.
SECONDARY OBJECTIVES:
I. Assessing time to biochemical recurrence (BCR; PSA ≥ nadir PSA + 2 ng/mL) among patients initially meeting primary endpoint.
II. Assessing patient-reported genitourinary quality of life, as assessed by the Expanded Prostate Cancer Index Composite-26 (EPIC-26) survey instrument 24 months after radiotherapy completion.
III. Assessing patient-reported bowel quality of life, as assessed by the EPIC-26 survey instrument 24 months after radiotherapy completion.
IV. Assessing radiographic persistence of disease on a prostate specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) six months following hormonal therapy completion.
V. Assessing radiographic persistence of disease on a multiparametric MRI at fixed intervals (i.e., 6, 12, 18, 24, 30) months after radiotherapy completion.
VI. Assessment of longitudinal changes in patient-reported quality of life metrics on the EPIC-26 survey instrument.
VII. Physician-reported acute and late toxicities as per the Common Terminology Criteria for Adverse Events (CTCAE) scale version (v)5.0.
OUTLINE:
Patients receive apalutamide orally (PO) once daily (QD) on days 1-28 of each cycle. Cycles repeat every 28 days for up to 6 or 12 months in the absence of disease progression or unacceptable toxicity. Patients undergo SBRT for 5 fractions over 1-2 weeks beginning on day 1 of cycle 1. Patients also undergo multiparametric MRI and collection of blood samples throughout the trial. Patients undergo PSMA-PET/CT scans during screening and follow up.
After completion of study treatment, patients are followed up every 3 months for up to 24 months after SBRT and then up to 60 months after SBRT.
6,370 studies on the registry are indexed under Prostatic Neoplasms; 1,400 are open to participants now.
This study's planned enrollment of 95 is above the median of 58 across 4,822 interventional studies indexed under Prostatic Neoplasms.
Browse Prostatic Neoplasms studies →Jonsson Comprehensive Cancer Center is the lead sponsor of 396 studies on the registry; 67 are open to participants now.
Of its 37 completed or terminated interventional studies of FDA-regulated products, 2 (5%) have results posted.
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Exclusion Criteria:
History of any of the following:
Current evidence of any of the following:
Patients receive apalutamide PO QD on days 1-28 of each cycle. Cycles repeat every 28 days for up to 6 or 12 months in the absence of disease progression or unacceptable toxicity. Patients undergo SBRT for 5 fractions over 1-2 weeks beginning on day 1 of cycle 1. Patients also undergo multiparametric MRI and collection of blood samples throughout the trial. Patients undergo PSMA-PET/CT scans during screening and follow up.
Drug: Apalutamide · Procedure: Biospecimen Collection · Procedure: Computed Tomography · Other: Gallium Ga 68 Gozetotide · Radiation: Guided Stereotactic Body Radiation Therapy · Procedure: Multiparametric Magnetic Resonance Imaging · Procedure: Positron Emission Tomography · Other: Questionnaire Administration
Given PO
Also known as: ARN 509, ARN-509, ARN509, Erleada, JNJ 56021927, JNJ-56021927
Undergo collection of blood samples
Also known as: Biological Sample Collection, Biospecimen Collected, Specimen Collection
Undergo PSMA-PET/CT
Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, CT, CT Scan, tomography
Undergo PSMA-PET/CT
Also known as: (68)Ga labeled Glu-NH-CO-NH-Lys(Ahx)-HBED-CC, (68)Ga-labeled Glu-urea-Lys(Ahx)-HBED-CC, (68)Ga-PSMA Ligand Glu-urea-Lys(Ahx)-HBED-CC, (68)Gallium-PSMA Ligand Glu-urea-Lys(Ahx)-HBED-CC, (68Ga)Glu-urea-Lys(Ahx)-HBED-CC, 68Ga-DKFZ-PSMA-11, 68Ga-HBED-CC-PSMA, 68Ga-labeled Glu-NH-CO-NH-Lys(Ahx)-HBED-CC, 68Ga-PSMA, 68Ga-PSMA-11, 68Ga-PSMA-HBED-CC, [68Ga] Prostate-specific Membrane Antigen 11, [68Ga]GaPSMA-11, AAA 517, AAA-517, AAA517, Ga PSMA, Ga-68 labeled DKFZ-PSMA-11, Ga-68 labeled PSMA-11, GA-68 PSMA-11, Gallium Ga 68 PSMA-11, Gallium Ga 68-labeled PSMA-11, GALLIUM GA-68 GOZETOTIDE, Gallium-68 PSMA, Gallium-68 PSMA Ligand Glu-urea-Lys(Ahx)-HBED-CC, GaPSMA, PSMA-HBED-CC GA-68
Undergo guided SBRT
Undergo multiparametric MRI
Also known as: MP-MRI, mpMRI, Multi-parametric MRI, Multiparametric MRI
Undergo PSMA-PET/CT
Also known as: Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron emission tomography (procedure), Positron Emission Tomography Scan, Positron-Emission Tomography, proton magnetic resonance spectroscopic imaging, PT
Ancillary studies
Percent of patients achieving prostate specific antigen (PSA) of < 0.2 ng/mL
Will be summarized by count and percent along with the 95% confidence interval. This will then be compared to the historical control rate of 70% using a two sample z test for proportions with a one-sided p-value threshold of 0.05.
Time frame: Three months after completion of apalutamide
Time to biochemical recurrence (BCR)
Evaluated among patients initially meeting the primary endpoint. BCR is defined as PSA \>= nadir PSA + 2 ng/mL. Time to BCR will be reported descriptively for each patient. Five-year biochemical recurrence free survival will be estimated by the Kaplan-Meier method as well as descriptively (mean, standard deviation, median, first and third quartiles, minimum, maximum).
Time frame: We will follow patients for five years following completion of radiotherapy. Biochemical disease status will be checked every 3 months for the first year, and every 6 months thereafter.
Patient-reported outcomes (PROs) on the Expanded Prostate Cancer Index Composite-26 (EPIC-26) urinary domain
Changes will be analyzed with respect to whether they represent minimally important differences.
Time frame: 24 months after completion of stereotactic body radiation therapy (SBRT)
PROs on the EPIC-26 bowel domain
The analysis of both acute and late changes in the bowel domain of the EPIC instrument will be stratified for use of hydrogel spacers or not, as these may reduce both acute and late gastrointestinal bowel symptoms.
Time frame: 24 months after completion of SBRT
Radiographic persistence of disease on prostate specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)
Defined by expert reader using the criterion of standardized uptake value within 20% of pre-SBRT PSMA PET/CT. Will be reported as a binary value (persistent versus not persistent).
Time frame: 6 months after hormonal therapy completion
Radiographic persistence of disease on multiparametric magnetic resonance imaging
Defined by expert reader using a composite of apparent diffusion coefficient, size, and ktrans. Will be reported as a binary value (persistent vs. not persistent).
Time frame: At 6 months, 12 months, 18 months, 24 and 30 months after radiotherapy completion
Longitudinal PROs on the EPIC-26 questionnaire in the sexual, urinary, and bowel domains
For the EPIC-26 instrument, these will be represented by changes from baseline in the urinary incontinence, urinary obstruction, bowel, sexual function, and hormone/vitality domains. Changes will be analyzed with respect to whether they represent minimally important differences.
Time frame: Up to 60 months
Physician-reported acute and late toxicities
Evaluated per the Common Terminology Criteria for Adverse Events scale version 5.0. Rates will be reported descriptively. The 5-year cumulative incidences of late grade ≥ 2 genitourinary and gastrointestinal toxicity will be analyzed using a cumulative incidence framework. The analysis of gastrointestinal toxicities (acute and late) will be stratified by the use of hydrogel spacers.
Time frame: We will follow patients for five years following completion of radiotherapy. Acute toxicity will be scored within the first 90 days after radiation. Late toxicity and patient-reported outcomes will be assessed every 3 months for the first year, and every
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