Updated June 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

SRT Versus SRT+ADT in Prostate Cancer

Stereotactic Prostate Radiotherapy With or Without Androgen Deprivation Therapy, a Phase III, Multi-institutional Randomized-controlled Trial. The SPA Trial.

SRT Versus SRT+ADT in Prostate Cancer (NCT05019846) is a Phase 3 interventional studying Prostate Cancer, sponsored by Marco Lorenzo Bonu. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

To clarify the role of short-term Androgen deprivation therapy (ADT) in the context of intermediate unfavorable and a subclass of high-risk patients treated with prostate Stereotactic radiotherapy (SRT). In intermediate unfavorable risk group, when choosing standard external beam radiotherapy, short term ADT is superior in terms of biochemical disease free survival (bDFS) to EBRT alone. In high risk disease, results of the combination therapy are even more clear. Prostate SRT has been endorsed as option for primary radical treatment for prostate cancer. In such patients, the benefit of ADT is still unknown and the decision is left to clinical judgement. For these reasons, it seems to be relevant to propose a randomized, open label, phase III clinical trial of prostate SBRT + 6 months ADT versus prostate SBRT alone in intermediate unfavorable and a subgroup of high risk prostate cancer patients.

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Prostate Cancer, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 310 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: - Histological confirmation of prostate acinar adenocarcinoma with a minimum of 10 biopsy cores taken - Prostate protocol MRI for local staging - Patients belonging to intermediate unfavorable group according to the D'Amico/NCCN risk group classification: - -Grade group 3 or/and - -2-3 risk factors for intermediate category (PSA 10-20 ng/ml/ Grade group 2-3/ cT2b cT2c) or/and - -biopsy cores positive ≥50% - Patients belonging to a subclass of high risk group according to the D'Amico/NCCN risk group classification: - -ISUP group 4 (GS 4+4, 3+5, 5+3) or - -cT3a stage or - PSA\>20 - Eastern Coooperative Oncology Group (ECOG) PS 0-2 - Ability of the patient to understand and sign a written willing to sign a consent form document - Ability and willingness to comply with patients reported outcome questionnaires schedule during the study time - IPSS 0-15 - Prostate Volume less than 100cc - PSA must be dosed maximum 60 days before randomization - No pathologic lymph nodes and distant metastasis on PET (fluorocholine) scan or CT scan+bone scan. - Contraceptive measures for patients with partners with reproductive potential must be explained Who Should NOT Join This Trial: - History of Malignant tumors in the previous 2 years excluding non melanoma cancers of the skin. If a patient presents an anamnesis of malignancy (excluding non melanoma skin cancers) it must be free from disease since 24 months at the time of enrollement. - Previous prostate surgery other than TURP (at least 6 weeks prior to start of SBRT). - Previous pelvic RT - Prior androgen deprivation therapy (excluding 5alpha reductase inhibitors) - Any prior active treatment for prostate cancer; patients on previous active surveillance are eligible if inclusion criteria are met - Active severe inflammatory bowel disease - Bilateral hip prothesis or any implant that could seriously interfere with dosimetric calculations - Age \>80 years. - cT4a, cT3b or pelvic lymph node involvement ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Histological confirmation of prostate acinar adenocarcinoma with a minimum of 10 biopsy cores taken * Prostate protocol MRI for local staging * Patients belonging to intermediate unfavorable group according to the D'Amico/NCCN risk group classification: * -Grade group 3 or/and * -2-3 risk factors for intermediate category (PSA 10-20 ng/ml/ Grade group 2-3/ cT2b cT2c) or/and * -biopsy cores positive ≥50% * Patients belonging to a subclass of high risk group according to the D'Amico/NCCN risk group classification: * -ISUP group 4 (GS 4+4, 3+5, 5+3) or * -cT3a stage or * PSA\>20 * Eastern Coooperative Oncology Group (ECOG) PS 0-2 * Ability of the patient to understand and sign a written informed consent document * Ability and willingness to comply with patients reported outcome questionnaires schedule during the study time * IPSS 0-15 * Prostate Volume less than 100cc * PSA must be dosed maximum 60 days before randomization * No pathologic lymph nodes and distant metastasis on PET (fluorocholine) scan or CT scan+bone scan. * Contraceptive measures for patients with partners with reproductive potential must be explained Exclusion Criteria: * History of Malignant tumors in the previous 2 years excluding non melanoma cancers of the skin. If a patient presents an anamnesis of malignancy (excluding non melanoma skin cancers) it must be free from disease since 24 months at the time of enrollement. * Previous prostate surgery other than TURP (at least 6 weeks prior to start of SBRT). * Previous pelvic RT * Prior androgen deprivation therapy (excluding 5alpha reductase inhibitors) * Any prior active treatment for prostate cancer; patients on previous active surveillance are eligible if inclusion criteria are met * Active severe inflammatory bowel disease * Bilateral hip prothesis or any implant that could seriously interfere with dosimetric calculations * Age \>80 years. * cT4a, cT3b or pelvic lymph node involvement * Controindication or hypersensitivity to the use of Triptoreline * 5alpha reductase inhibitors not discontinued 4 weeks prior to randomization * History of bone fractures and fall * Risk factors for abnormal heart rhythms or QT prolongation. * Use of concomitant medications that prolong the QT/QTc interval

Treatments Being Tested

DRUG

Triptorelin Embonate

single administration before SRT starting

DRUG

Bicalutamide 50 mg

1 dose each day, 7 days before LHRH until 10 days after LHRH administration

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

ASST Spedali Civili of Brescia

Brescia, BS, Italy

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05019846), the sponsor (Marco Lorenzo Bonu), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05019846 clinical trial studying?

To clarify the role of short-term Androgen deprivation therapy (ADT) in the context of intermediate unfavorable and a subclass of high-risk patients treated with prostate Stereotactic radiotherapy (SRT). In intermediate unfavorable risk group, when choosing standard external beam radiotherapy, short term ADT is superior in terms of biochemical disease free survival (bDFS) to EBRT alone. In high risk disease, results of the combination therapy are even more clear. Prostate SRT has been endorsed as option for primary radical treatment for prostate cancer. In such patients, the benefit of ADT is… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05019846?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05019846?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

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Source: ClinicalTrials.gov API v2 record for NCT05019846. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05019846. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-26 · Data from ClinicalTrials.gov.