Prostatic NeoplasmsPhase 2NCT03007732
Pembrolizumab +/- SD-101 in Hormone-Naïve Oligometastatic Prostate Cancer With RT and iADT
A Phase 2 study testing Pembrolizumab, SD-101 and Leuprolide acetate in people with Prostatic Neoplasms, run by David Oh at 1 site in United States.
Trial summary
This is a non-comparative open-label multicenter Phase 2 clinical trial combining stereotactic body radiation therapy (SBRT) and pembrolizumab with or without intratumoral SD-101 in participants with newly diagnosed hormone-naive oligometastatic prostate cancer. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Prostatic Neoplasms
- What is being tested?
- Pembrolizumab, SD-101 and Leuprolide acetate
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 23 participants
- Where
- 1 siteUnited States
- Study dates
- 17 May 2017to 31 Mar 2025
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Be willing and able to provide written informed consent/assent for the trial.
- Be >=18 years of age on day of signing informed consent.
- Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale.
- Histologically documented adenocarcinoma of the prostate
- Oligometastatic disease. In order to be eligible, the participant must have a total of <4 metastatic bone and/or metastatic lymph node sites based on bone and/or soft tissue lesions as defined by any of the following:
- Bone metastases will be defined by bone imaging. If the participant has technetium bone scan, and/or sodium fluoride (NaF) PET performed, either study may be used for documenting metastases; both scans do not need to show the number of metastases required for study entry. For participants undergoing PSMA PET, only PSMA avid lesions that are consistent with metastasis will be counted as a site of metastasis.
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- Distant metastatic lymph node disease. A lymph node ≥1 cm in shortest dimension will be noted as involved with disease. Distant metastatic lymph nodes will be determined as any lymph nodes outside the confines of the true pelvis. For participants undergoing PSMA PET, only PSMA avid lesions that are consistent with metastasis will be counted as a site of metastasis.
- Any other soft tissue lesion deemed by the physician to be consistent with distant metastatic disease. For participants undergoing PSMA PET, only PSMA avid lesions that have a CT or MRI correlate consistent with metastasis will be counted as a site of metastasis.
- Note: Radiographic imaging performed as standard of care prior to obtaining informed consent and within 60 days of initiating study treatment may be used to assess oligometastatic disease during screening, rather than repeating scans. For participants who have started on ADT, they must have had imaging prior to initiation of hormonal therapy
- Treatment naïve, defined as less than 2 months of standard of care ADT (e.g. GnRH agonist or antagonist with or without antiandrogen, including abiraterone) for metastatic hormone-sensitive prostate cancer prior to enrollment (at the time of consent)
- No prior chemotherapy for prostate cancer
- Not a candidate for or refuse chemotherapy
- No prior prostatectomy or prostatic radiation
- PSA >2 ng/mL at baseline or prior to initiation of hormonal therapy
- Baseline testosterone >150 ng/dL if participant has not initiated hormonal therapy, for those participants who have already initiated hormonal therapy, baseline testosterone is not required
- Consent to undergo mandatory prostatic core biopsies at the time of fiducial marker placement and 1-3 weeks after Cycle 1 Day 1 of pembrolizumab.
- The effects of pembrolizumab on the developing human fetus is unknown. Men treated or enrolled on this protocol must agree to use adequate contraception prior to the first dose of study therapy, for the duration of the study participation, and for 120 days after the last dose of study therapy. Their partners should also be encouraged to use proper method of contraception. Their partners should also be encouraged to use proper method of contraception.
- Demonstrate adequate organ function defined as: Adequate Organ Function Laboratory Values (Performed within 10 days of treatment initiation):
- Absolute neutrophil count (ANC) ≥1,500 /microliter (mcL)
- Platelets >=100,000 / mcL
- Hemoglobin >=9 g/dL or ≥5.6 mmol/L without transfusion or erythropoietin (EPO) dependency (within 7 days of assessment)
- Serum creatinine OR Measured or calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) <=1.5 X upper limit of normal (ULN) OR ≥60 mL/min for subject with creatinine levels > 1.5 X institutional ULN. Creatinine clearance should be calculated per institutional standard
- Serum total bilirubin <= 1.5 X ULN OR Direct bilirubin <= ULN for subjects with total bilirubin levels > 1.5 ULN
- Aspartate aminotransferase (AST) (SGOT) and alanine aminotransferase (ALT) (SGPT) ≤ 2.5 X ULN OR ≤ 5 X ULN for subjects with liver metastases
- Albumin >2.5 mg/dL
- International Normalized Ratio (INR) or Prothrombin Time (PT)
- Activated Partial Thromboplastin Time (aPTT) ≤1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants ≤1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants
- Creatinine clearance should be calculated per institutional standard.
Who cannot join
- Participants who are not appropriate candidates for prostate or oligometastasis-directed SBRT
- Participants with neuroendocrine or small cell features are not eligible.
- Participants with evidence of liver metastasis are excluded.
- Gonadotropin-releasing hormone (GnRH) agonists or GnRH antagonists (e.g., leuprorelin, degarelix) for > 2 months prior to consenting
- Antiandrogens (e.g., bicalutamide, flutamide, nilutamide, abiraterone, enzalutamide) for > 2 months prior to consenting. Participants on 5-alpha reductase inhibitors are allowed on study.
- Estrogen containing compounds for > 2 months prior to consenting
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- PC-SPES or PC-x products. Other herbal therapies or supplements will be considered by the Principle Investigator on a case-by-case basis based on their potential for hormonal or anti-cancer therapies.
- Prior immunotherapy or chemotherapy for prostate cancer
- Prior radiation therapy to the prostate
- Prior prostatectomy
- Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks of the first dose of treatment.
- Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of systemic immunosuppressive therapy within 7 days prior to the first dose of trial treatment, with the exception of steroids for adrenal insufficiency in which case prednisone =<10mg/day or its equivalent is allowed.
- Has a known history of active Bacillus Tuberculosis (TB)
- Hypersensitivity to pembrolizumab or any of its excipients.
- Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to agents administered more than 4 weeks earlier.
- Has had prior chemotherapy, targeted small molecule therapy, or radiation therapy within 2 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to a previously administered agent.
- Note: Subjects with <= Grade 2 neuropathy are an exception to this criterion and may qualify for the study.
- Note: If subject received major surgery, they must have recovered adequately from the toxicity and/or complications from the intervention prior to starting
- Has a known additional malignancy that is progressing or requires active treatment. Exceptions include carcinoid, basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer.
- Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Subjects with previously treated brain metastases may participate provided they are stable (without evidence of progression by imaging for at least four weeks prior to the first dose of trial treatment and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroid treatment for at least 14 days prior to the first dose of study treatment. This exception does not include carcinomatous meningitis which is excluded regardless of clinical stability.
- Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment.
- Has known history of, or any evidence of active, non-infectious pneumonitis.
- Has an active infection requiring systemic therapy.
- Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.
- Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial.
- Expecting to father children within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment.
- Has received prior therapy with an anti-programmed cell death protein 1 (PD-1), anti-programmed death-ligand 1 (PD-L1) , or anti-Programmed cell death 1 ligand 2 (PD-L2) agent.
- Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies).
- Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C (HCV) (i.e. HCV RNA [qualitative] is detected).
- Has received a live vaccine within 30 days of planned start of study therapy. a. Note: Seasonal influenza vaccines for injection are generally inactivated flu vaccines and are allowed; however intranasal influenza vaccines (e.g., Flu-Mist®) are live attenuated vaccines, and are not allowed within 30 days.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of California San Francisco
San Francisco, California, 94143
About this study
Official title: Phase 2 Trial Pembrolizumab or Pembrolizumab in Combination With Intratumoral SD-101 Therapy in Patients With Hormone-Naïve Oligometastatic Prostate Cancer Receiving Stereotactic Body Radiation Therapy and Intermittent Androgen Deprivation Therapy
This is a non-comparative open-label multicenter Phase 2 clinical trial combining stereotactic body radiation therapy (SBRT) and pembrolizumab with or without intratumoral SD-101 in participants with newly diagnosed hormone-naive oligometastatic prostate cancer.
Read the detailed description
This randomized phase II trial studies how well androgen deprivation therapy, pembrolizumab, and stereotactic body radiation therapy with or without toll-like receptor 9 (TLR9) agonist SD-101 in treating participants with prostate cancer and cancer in all oligometastatic sites that has spread to other places in the body. Androgen can cause the growth of tumor cells. Androgen deprivation therapy, such as leuprolide acetate, prednisone, and abiraterone acetate may lessen the amount of androgen made by the body. Monoclonal antibodies, such as pembrolizumab, may interfere with the ability of tumor cells to grow and spread. Stereotactic body radiation therapy is a specialized radiation therapy that sends x-rays directly to the tumor using smaller doses over several days and may cause less damage to normal tissue. Colony-stimulating factors, such as TLR9 agonist SD-101, may increase the production of blood cells. It is not yet known whether giving androgen deprivation therapy, pembrolizumab, and stereotactic body radiation therapy with or without TLR9 agonist SD-101 may work better in treating participants with prostate cancer and cancer in all oligometastatic sites.
PRIMARY OBJECTIVES
COHORT 1:
-- To assess the safety associated with giving RT and pembrolizumab with or without intratumoral SD-101.
COHORT 2:
- To continue to assess the safety associated with giving RT and pembrolizumab with or without intratumoral SD-101.
- To assess if the rate of PSA < nadir + 2 ng/mL at 15 months in participants with non-castrate levels of testosterone is greater than the historical control in each study arm.
SECONDARY OBJECTIVES
COHORT 2 ONLY:
- To determine the rate of testosterone-prostate specific antigen (PSA) uncoupling in each study arm in Cohort 2. Testosterone-PSA uncoupling is defined as PSA < 50% baseline and < 20ng/mL for at least 3 months after testosterone recovers to >150 ng/dL. In participants with metastatic hormone sensitive prostate cancer off hormonal therapy, >90% of participants are expected to have PSA increase to > 50% baseline after 3 months of testosterone recovery.
- To estimate time to clinical progression in each study arm in Cohort 2.
- To estimate progression-free survival (PFS) in each study arm Cohort 2.
EXPLORATORY OBJECTIVE
- To assess peripheral and tumor-based biomarkers of response and resistance in both cohorts.
- To define the treatment-induced effects on circulating immune cells in both cohorts.
- To explore remodeling of circulating T cell repertoire in both cohorts.
- To explore the concordance of Prostate-Specific Membrane Antigen (PSMA) - Positron Emission Tomography (PET) scanning with conventional imaging in oligometastatic prostate cancer participants in both cohorts.
- Conditions
- Prostatic Neoplasms
- Being tested
- Pembrolizumab, SD-101, Leuprolide acetate, Abiraterone Acetate, Prednisone
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PembrolizumabDrug
Also called MK-3475, Keytruda
200 mg IV every 21 days for up to 13 doses (Arms 1 and 2)
SD-101Drug
Also called Toll-like receptor 9
5 mg will be delivered to the dominant prostatic tumor lesion at time of fiducial marker placement (1-5 weeks prior to Cycle 1, Day 1) and and 1-3 weeks after Cycle 1 Day 1
Leuprolide acetateDrug
Also called Intermittent androgen deprivation therapy
22.5 mg will be given intramuscularly (IM). First injection 3 months prior to Cycle 1 Day 1. Intermittent androgen deprivation therapy will be given every 3 months starting Cycle 1, Day 1 for 3 additional doses.
Abiraterone AcetateDrug
Also called Intermittent androgen deprivation therapy
1000 mg oral dosage will be given daily for 3 months prior to Cycle 1, Day 1 and daily for 9 months starting Cycle 1, Day 1.
PrednisoneDrug
Also called Intermittent androgen deprivation therapy
5 mg oral dosage will be given daily for 3 months prior to Cycle 1 Day 1 and daily for 9 months starting Cycle 1, Day 1.
Stereotactic Body Radiation TherapyRadiation
Also called SBRT
7 Gy x 5 fractions (35 Gy total) 1-2 weeks after fiducial marker placement and simulation over 10-14 days.
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1, Arm 1: Prostate Only Sites (ADT, SBRT, Pembrolizumab) | Experimental | Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
| Cohort 1, Arm 2: Prostate Only Sites (ADT, SBRT, Pembrolizumab, SD-101) | Experimental | Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. TLR9 agonist SD-101: Injected into the dominant prostatic tumor lesion at time of fiducial marker placement (1-5weeks prior to Cycle 1 Day 1) and 1-3 weeks after Cycle 1 Day 1 Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
| Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab) | Experimental | Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1.
Pembrolizumab: Given IV every 21 days for up to 13 doses
Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland and oligometastatic sites via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. Receives: Drug: Pembrolizumab; Drug: Leuprolide acetate; Drug: Abiraterone Acetate; Drug: Prednisone; Radiation: Stereotactic Body Radiation Therapy |
| Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) | Experimental | Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1.
TLR9 agonist SD-101: Injected into the dominant prostatic tumor lesion at time of fiducial marker placement (1-5weeks prior to Cycle 1 Day 1) and 1-3 weeks after Cycle 1 Day 1
Pembrolizumab: Given IV every 21 days for up to 13 doses
Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland and oligometastatic sites via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. Receives: Drug: Pembrolizumab; Drug: SD-101; Drug: Leuprolide acetate; Drug: Abiraterone Acetate; Drug: Prednisone; Radiation: Stereotactic Body Radiation Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change Rate of Prostate-specific Antigen (PSA) < Nadir + 2 ng/mL From First Day of Treatment to 15 Months (Cohort 2)
Only participants in cohort 2, who achieve testosterone recovery to non-castrate levels (>150 ng/dL) at 15 months, will be analyzed for the primary endpoint. The rate of PSA < nadir + 2 ng/mL at 15 months from the start of radiotherapy and cycle 1, day 1 of pembrolizumab, among participants whose testosterone recovers to non-castrate levels (>150 ng/dL). The point estimate of the rate of PSA < nadir + 2 ng/mL will be obtained with its 95% confidence interval for participants by arm in cohort 2. All participants who receive any part of a dose of RT, SD-101 or pembrolizumab will be analyzed for efficacy.
Measured: Start of treatment and 15 months (approx. 15 months total)
Number of Participants With Treatment-related Adverse Events
Adverse events occurring on study will be summarized for all participants that received study intervention (including pembrolizumab, SD-101, SBRT to prostate, SBRT to oligometastatic sites) by maximum toxicity grade across study arms.
Measured: Up to 15 months
Secondary outcomes (3)
Rate of Testosterone-PSA Uncoupling (Cohort 2)
Testosterone-PSA uncoupling is defined as PSA < 50% baseline and < 20ng/mL for at least 3 months after testosterone recovers to >150 ng/dL. In participants with metastatic hormone-sensitive prostate cancer off hormonal therapy, >90% participants are expected to have PSA increase to > 50% baseline after 3 months of testosterone recovery. Therefore, the presence of PSA testosterone uncoupling in this study may serve as a surrogate of immunotherapeutic responses induced by pembrolizumab combined with RT (arm 1), or RT with SD-101 (arm 2), if a prolonged PSA < nadir + 2 ng/mL is not achieved. The point estimate of testosterone-PSA uncoupling rate will be obtained with its 95% confidence interval for each arm in cohort 2.
Measured: Up to 15 months
Median Time to Clinical Progression (Cohort 2)
The time to clinical progression in each study arm in cohort 2 is defined as the time to radiographic progression by Prostate Specific Antigen Working Group-2 (PSAWG2) criteria, time to symptomatic progressive disease, or PSA progression, whichever comes the first. Kaplan-Meier estimate will be obtained for the time to clinical progression in each study arm in cohort 2
Measured: Up to 3 years
Median Progression-free Survival (PFS) (Cohort 2)
Progression-free survival (PFS) will be estimated for each study arm on cohort 2 by Kaplan-Meier estimate, where PFS is a composite endpoint based on PSA progression, radiological progression, clinical deterioration, or death.
Measured: Up to 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jan 2017 (estimated)
- Study start17 May 2017
- Primary completion31 Mar 2025
- Study completion31 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Prostatic NeoplasmsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 23 participants (actual)
Sponsor and investigators
- Lead sponsor
- David Oh
- Sponsor type
- University, hospital or other
- Collaborators
- Prostate Cancer Foundation, Merck Sharp & Dohme LLC, TriSalus Life Sciences, Inc.
- Responsible party
- Sponsor-investigator, David Oh, University of California, San Francisco
- Investigators
- David Oh, MD, PhD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03007732
- Sponsor's protocol ID
- 16703
- Other IDs
- NCI-2017-01340
- Status last verified
- Nov 2025
- First submitted
- 5 Aug 2016
- Last updated
- 5 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase 2 Trial Pembrolizumab or Pembrolizumab in Combination With Intratumoral SD-101 Therapy in Patients With Hormone-Naïve Oligometastatic Prostate Cancer Receiving Stereotactic Body Radiation Therapy and Intermittent Androgen Deprivation Therapy
- ClinicalTrials.gov ID
- NCT03007732
- Acronym / sponsor ID
- 16703
- Conditions
- Prostatic Neoplasms
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 23 participants (actual)
- Lead sponsor
- David OhUniversity, hospital or other
- Collaborators
- Prostate Cancer Foundation, Merck Sharp & Dohme LLC, TriSalus Life Sciences, Inc.
- Study start
- 17 May 2017 (actual)
- Primary completion
- 31 Mar 2025 (actual)
- Study completion
- 31 Mar 2025 (actual)
- First posted
- 2 Jan 2017 (estimated)
- Results
- Posted 5 Dec 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a non-comparative open-label multicenter Phase 2 clinical trial combining stereotactic body radiation therapy (SBRT) and pembrolizumab with or without intratumoral SD-101 in participants with newly diagnosed hormone-naive oligometastatic prostate cancer.
Detailed description
This randomized phase II trial studies how well androgen deprivation therapy, pembrolizumab, and stereotactic body radiation therapy with or without toll-like receptor 9 (TLR9) agonist SD-101 in treating participants with prostate cancer and cancer in all oligometastatic sites that has spread to other places in the body. Androgen can cause the growth of tumor cells. Androgen deprivation therapy, such as leuprolide acetate, prednisone, and abiraterone acetate may lessen the amount of androgen made by the body. Monoclonal antibodies, such as pembrolizumab, may interfere with the ability of tumor cells to grow and spread. Stereotactic body radiation therapy is a specialized radiation therapy that sends x-rays directly to the tumor using smaller doses over several days and may cause less damage to normal tissue. Colony-stimulating factors, such as TLR9 agonist SD-101, may increase the production of blood cells. It is not yet known whether giving androgen deprivation therapy, pembrolizumab, and stereotactic body radiation therapy with or without TLR9 agonist SD-101 may work better in treating participants with prostate cancer and cancer in all oligometastatic sites.
PRIMARY OBJECTIVES
COHORT 1:
-- To assess the safety associated with giving RT and pembrolizumab with or without intratumoral SD-101.
COHORT 2:
- To continue to assess the safety associated with giving RT and pembrolizumab with or without intratumoral SD-101.
- To assess if the rate of PSA < nadir + 2 ng/mL at 15 months in participants with non-castrate levels of testosterone is greater than the historical control in each study arm.
SECONDARY OBJECTIVES
COHORT 2 ONLY:
- To determine the rate of testosterone-prostate specific antigen (PSA) uncoupling in each study arm in Cohort 2. Testosterone-PSA uncoupling is defined as PSA < 50% baseline and < 20ng/mL for at least 3 months after testosterone recovers to >150 ng/dL. In participants with metastatic hormone sensitive prostate cancer off hormonal therapy, >90% of participants are expected to have PSA increase to > 50% baseline after 3 months of testosterone recovery.
- To estimate time to clinical progression in each study arm in Cohort 2.
- To estimate progression-free survival (PFS) in each study arm Cohort 2.
EXPLORATORY OBJECTIVE
- To assess peripheral and tumor-based biomarkers of response and resistance in both cohorts.
- To define the treatment-induced effects on circulating immune cells in both cohorts.
- To explore remodeling of circulating T cell repertoire in both cohorts.
- To explore the concordance of Prostate-Specific Membrane Antigen (PSMA) - Positron Emission Tomography (PET) scanning with conventional imaging in oligometastatic prostate cancer participants in both cohorts.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Cohort 1, Arm 1: Prostate Only Sites (ADT, SBRT, Pembrolizumab) | Experimental | –Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
| Cohort 1, Arm 2: Prostate Only Sites (ADT, SBRT, Pembrolizumab, SD-101) | Experimental | –Three month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. TLR9 agonist SD-101: Injected into the dominant prostatic tumor lesion at time of fiducial marker placement (1-5weeks prior to Cycle 1 Day 1) and 1-3 weeks after Cycle 1 Day 1 Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
| Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab) | Experimental | Drug: Pembrolizumab, Drug: Leuprolide acetate, Drug: Abiraterone Acetate, Drug: Prednisone, Radiation: Stereotactic Body Radiation TherapyThree month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland and oligometastatic sites via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
| Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) | Experimental | Drug: Pembrolizumab, Drug: SD-101, Drug: Leuprolide acetate, Drug: Abiraterone Acetate, Drug: Prednisone, Radiation: Stereotactic Body Radiation TherapyThree month androgen deprivation therapy (ADT) run-in followed by leuprolide injected intramuscularly every 3 months for 3 doses (or another FDA approved gonadotropin-releasing hormone agent for 9 months) + abiraterone by mouth daily with prednisone by mouth daily (or equivalent medication per local standard practice) for 9 months starting on Day 1. TLR9 agonist SD-101: Injected into the dominant prostatic tumor lesion at time of fiducial marker placement (1-5weeks prior to Cycle 1 Day 1) and 1-3 weeks after Cycle 1 Day 1 Pembrolizumab: Given IV every 21 days for up to 13 doses Radiotherapy: Given every other day over 10-14 days delivered to the whole prostate gland and oligometastatic sites via stereotactic body radiation therapy (SBRT) starting 1-2 weeks after marker placement. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (28 listed)
- Be willing and able to provide written informed consent/assent for the trial.
- Be >=18 years of age on day of signing informed consent.
- Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale.
- Histologically documented adenocarcinoma of the prostate
- Oligometastatic disease. In order to be eligible, the participant must have a total of <4 metastatic bone and/or metastatic lymph node sites based on bone and/or soft tissue lesions as defined by any of the following:
Key exclusion criteria (30 listed)
- Participants who are not appropriate candidates for prostate or oligometastasis-directed SBRT
- Participants with neuroendocrine or small cell features are not eligible.
- Participants with evidence of liver metastasis are excluded.
- Gonadotropin-releasing hormone (GnRH) agonists or GnRH antagonists (e.g., leuprorelin, degarelix) for > 2 months prior to consenting
- Antiandrogens (e.g., bicalutamide, flutamide, nilutamide, abiraterone, enzalutamide) for > 2 months prior to consenting. Participants on 5-alpha reductase inhibitors are allowed on study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PembrolizumabAlso: MK-3475, Keytruda200 mg IV every 21 days for up to 13 doses (Arms 1 and 2) | Drug | Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab), Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
| SD-101Also: Toll-like receptor 95 mg will be delivered to the dominant prostatic tumor lesion at time of fiducial marker placement (1-5 weeks prior to Cycle 1, Day 1) and and 1-3 weeks after Cycle 1 Day 1 | Drug | Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
| Leuprolide acetateAlso: Intermittent androgen deprivation therapy22.5 mg will be given intramuscularly (IM). First injection 3 months prior to Cycle 1 Day 1. Intermittent androgen deprivation therapy will be given every 3 months starting Cycle 1, Day 1 for 3 additional doses. | Drug | Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab), Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
| Abiraterone AcetateAlso: Intermittent androgen deprivation therapy1000 mg oral dosage will be given daily for 3 months prior to Cycle 1, Day 1 and daily for 9 months starting Cycle 1, Day 1. | Drug | Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab), Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
| PrednisoneAlso: Intermittent androgen deprivation therapy5 mg oral dosage will be given daily for 3 months prior to Cycle 1 Day 1 and daily for 9 months starting Cycle 1, Day 1. | Drug | Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab), Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
| Stereotactic Body Radiation TherapyAlso: SBRT7 Gy x 5 fractions (35 Gy total) 1-2 weeks after fiducial marker placement and simulation over 10-14 days. | Radiation | Cohort 2, Arm 1: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab), Cohort 2, Arm 2: Prostate and Oligometastatic sites (ADT, SBRT, Pembrolizumab, SD-101) |
Primary outcome
Change Rate of Prostate-specific Antigen (PSA) < Nadir + 2 ng/mL From First Day of Treatment to 15 Months (Cohort 2)
Time frame: Start of treatment and 15 months (approx. 15 months total)
Only participants in cohort 2, who achieve testosterone recovery to non-castrate levels (>150 ng/dL) at 15 months, will be analyzed for the primary endpoint. The rate of PSA < nadir + 2 ng/mL at 15 months from the start of radiotherapy and cycle 1, day 1 of pembrolizumab, among participants whose testosterone recovers to non-castrate levels (>150 ng/dL). The point estimate of the rate of PSA < nadir + 2 ng/mL will be obtained with its 95% confidence interval for participants by arm in cohort 2. All participants who receive any part of a dose of RT, SD-101 or pembrolizumab will be analyzed for efficacy.
Number of Participants With Treatment-related Adverse Events
Time frame: Up to 15 months
Adverse events occurring on study will be summarized for all participants that received study intervention (including pembrolizumab, SD-101, SBRT to prostate, SBRT to oligometastatic sites) by maximum toxicity grade across study arms.
3 secondary outcomes
Rate of Testosterone-PSA Uncoupling (Cohort 2)
Time frame: Up to 15 months
Median Time to Clinical Progression (Cohort 2)
Time frame: Up to 3 years
Median Progression-free Survival (PFS) (Cohort 2)
Time frame: Up to 3 years
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David Oh, MD, PhD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Pembrolizumab, SD-101 and Leuprolide acetate in people with Prostatic Neoplasms, run by David Oh at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 28 inclusion and 30 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 5 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change Rate of Prostate-specific Antigen (PSA) < Nadir + 2 ng/mL From First Day of Treatment to 15 Months (Cohort 2) (time frame: Start of treatment and 15 months (approx. 15 months total)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Dec 2025.