NCT05568550 · Zin W Myint
Pembro With Radiation With or Without Olaparib
What this study is about
This trial will evaluate whether the immune-sensitizing effects of immunotherapy (Pembrolizumab) and radiation with or without a PARP-inhibitor (Olaparib) will increase the effects of immunotherapy in men with high-risk localized prostate cancer.
View original scientific description
This trial will evaluate whether the immune-sensitizing effects of immunotherapy (Pembrolizumab) and radiation with or without a PARP-inhibitor (Olaparib) will increase the effects of immunotherapy in men with high-risk localized prostate cancer.
Interventions
BIOLOGICAL
Pembrolizumab
Pembrolizumab will be delivered via IV at 200mg on day 1 of each 3-week cycle for approximately 12 months. Cycle 1 begins 21 days prior to radiation therapy and cycles 2-17 are administered during and after radiation therapy.
DRUG
Olaparib
200mg Olaparib will be given twice daily for a total of 3 cycles. Cycle 1 begins 21-days prior to radiation therapy.
DRUG
Androgen Deprivation Therapy
Androgen Deprivation Therapy (either LHRH agonist or LHRH antagonist) as per treating physician choice will be allowed within 3 months prior to randomization. Duration is per institutional standards.
RADIATION
Radiation Therapy
Definitive radiation (total dose and fractions) will be dosed per institutional standards. Definitive radiation may include external beam radiation therapy with or without brachytherapy, based on NCCN risk score and as per treating physicians.
Primary outcome measures
Clinical Response Rate
Time frame: 6 months
The proportion of patients who achieve a PSA nadir level of ≤ 0.06ng/mL six months after completion of radiation therapy.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Male participants with histologically confirmed adenocarcinoma of the prostate
- High-risk / very high-risk status per NCCN guidelines
- ECOG performance status 0 to 1
- Regional lymph nodes are allowed.
- Agree to use contraception during the treatment period and for at least 120 days after the last dose of study intervention and refrain from donating sperm during this period.
- Ability to understand and the willingness to sign a written informed consent document.
- Adequate organ and marrow function
- Prior pharmacologic androgen ablation for prostate cancer is allowed only if the onset of androgen ablation is ≤90 days prior to the date of registration
- Prior 5-alpha reductase inhibitor (for example, finasteride) for prostatic hypertrophy is allowed if discontinued at least 60 days prior to registration.
- Known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac fun
Where
- Lexington, Kentucky
- Salt Lake City, Utah
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 14, 2026 · Source of record for eligibility and locations