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.
Confirmed diagnosis of prostate adenocarcinoma
Age ≥ 18
Classified as having National Comprehensive Cancer Network unfavorable intermediate risk prostate cancer (i.e., [a] 2 of the following: PSA 10-20 ng/mL, clinical T category 2b-2c, or International Society of Urological Pathology [ISUP] grade group 2; [b] OR any 1 of [a] with ISUP grade group 3 disease; OR [c] any 1 of [a] with 50% or more cores on systematic biopsy showing prostate cancer)
Have a Decipher genomic classifier score
Any evidence of spinal cord compression (radiological or clinical)
Prior pelvic malignancy
Prior pelvic radiation
Concurrent malignancy other than adequately treated basal cell or squamous cell skin cancer, non-muscle invasive bladder cancer (NMIBC), or any other cancer in situ currently without evidence of recurrence or progression
Single group
Apalutamide
DrugGiven PO
Biospecimen Collection
Procedure/SurgeryUndergo collection of blood samples
Computed Tomography
Procedure/SurgeryUndergo PSMA-PET/CT
Gallium Ga 68 Gozetotide
Other interventionUndergo PSMA-PET/CT
Guided Stereotactic Body Radiation Therapy
RadiationUndergo guided SBRT
Multiparametric Magnetic Resonance Imaging
Procedure/SurgeryUndergo multiparametric MRI
Positron Emission Tomography
Procedure/SurgeryUndergo PSMA-PET/CT
Questionnaire Administration
Other interventionAncillary 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 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).
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.
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.
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).
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Jonsson Comprehensive Cancer Center
Lead sponsor
Janssen Scientific Affairs, LLC
Collaborator
