Fractionated Stereotactic Radiotherapy Plus Second-generation Antiandrogen for Oligometastatic Castration-resistant Prostate Cancer Patients. (OLIGORESIST)

July 16, 2026 updated by: Instituto de Investigación en Oncología Radioterápica - Fundación Española de Oncología Radioterápic

Radioterapia estereotáctica Fraccionada más antiandrógeno de Segunda generación Para Pacientes oligometastásicos Con cáncer de próstata Resistente a la castración. Estudio español Fase II, Prospectivo, multicéntrico.

The objectives of the study are to analyze the results obtained in survival, safety and quality of life after the combination of SBRT plus second-generation antiandrogen in patients diagnosed with metastatic castration-resistant prostate cancer in oligometastasis (≤5).

Hence, the investigators evaluate the results of the combination of two widely used treatments in prostate cancer: SBRT plus the 'standard of care' for patients with mCRPC, second-generation antiandrogens (abiraterone and enzalutamide).

Primary objective: Determine the PRFS measured from the time of initiation of second-generation antiandrogen to the time of radiological progression by choline PET/CT or 68Ga-PSMA PET/CT, in patients with mCRPC treated with the combination of second-generation antiandrogen plus SBRT.

Secondary objectives:

  • Overall survival (time from initiation of second-generation antiandrogen to exitus) in patients with mCRPC treated with the combination of second-generation antiandrogen plus SBRT.
  • Quality of life of these patients using the European Organization for Research and Treatment of Cancer (EORTC) quality of life scale, EORTC QLQ-C30, validated for oncology patients.
  • Acute and chronic toxicity according to the "Common Terminology Criteria for Adverse Events" (CTCAEv5.0) scale.

This is a phase II, multicenter, prospective, single group study in patients with castrate-resistant prostate cancer (CRPC).

Patients will be recruited at the participant sites, after study approval and hospital authorization.

51 patients will be included in the study. Eligible patients will require:

  • Choline PET/CT or 68Ga-PSMA PET/CT, dated no more than 8 weeks prior to inclusion.
  • Clinical history, physical examination and functional evaluation scale (ECOG).
  • Geriatric assessment scale for patients > 75 years (modified G8 scale)
  • Toxicity scale assessment (CTCAEv5.0)
  • Baseline quality of life questionnaire (EORTC QLQ-C30) (47)
  • Blood tests with complete blood count, coagulation, liver function, renal function, ions, alkaline phosphatase, PSA and total and free testosterone, dated no more than 4 weeks prior inclusion.
  • Inclusion/exclusion criteria assessment
  • Second generation antiandrogen prescription, chosen by the responsible physician according to clinical practice, in each case.

Each patient will be included in the study once the second generation antiandrogen is initiated (which will be maintained until radiological progression, suspension due to poor tolerance and/or exitus). SBRT will be performed at least 2 weeks after initiating treatment with second generation antiandrogen, without exceeding 8 weeks from the start of treatment, and follow-up will continue up to a maximum of 36 months after completion of SBRT and/or exitus.

Recruitment time is estimated at 36 months and a total follow-up time of 36 months. The total duration of the trial is therefore expected to be 6 years, to allow complete follow-up of the last patients included.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

51

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Spain
    • Aragon
      • Zaragoza, Aragon, Spain, 50009
        • Active, not recruiting
        • Hospital Universitario Miguel Servet
    • Barcelona
      • Barcelona, Barcelona, Spain, 08036
        • Recruiting
        • Hospital Clínic de Barcelona
        • Contact:
        • Principal Investigator:
          • Joel Mases i Rosinés, MD
        • Sub-Investigator:
          • Elías Gomís, MD
        • Sub-Investigator:
          • Sara Moreno, MD
        • Sub-Investigator:
          • Gerard Meca, MD
      • L'Hospitalet de Llobregat, Barcelona, Spain, 08908
        • Recruiting
        • Instituto Catalán de Oncología Hospitalet
        • Contact:
        • Principal Investigator:
          • Ana María Boladeras Inglada, MD
    • Basque Country
      • Bilbao, Basque Country, Spain, 48013
        • Active, not recruiting
        • Hospital Universitario Basurto
    • Castille and León
      • Salamanca, Castille and León, Spain, 37007
        • Active, not recruiting
        • Hospital Universitario de Salamanca
      • Valladolid, Castille and León, Spain, 47003
        • Recruiting
        • Hospital Clínico Universitario de Valladolid
        • Contact:
        • Principal Investigator:
          • Patricia Diezhandino Garcia, MD
    • Catalonia
      • Barcelona, Catalonia, Spain, 08041
        • Recruiting
        • Hospital de la Santa Creu i Sant Pau
        • Contact:
        • Contact:
          • Saudy Peláez Bonilla, Study coordinator
          • Phone Number: 776 +34 935537760
          • Email: SPelaez@santpau.cat
        • Sub-Investigator:
          • Arantxa Mera Errasti, MD
        • Principal Investigator:
          • Gemma Sancho Pardo, MD
        • Sub-Investigator:
          • Laura Montezuma Niño, MD
        • Sub-Investigator:
          • Ana Maria Soto Cambres, MD
      • Terrassa, Catalonia, Spain, 08227
        • Active, not recruiting
        • Consorci Sanitari De Terrassa
    • Galicia
      • Santiago de Compostela, Galicia, Spain, 15706
        • Active, not recruiting
        • Complexo Hospitalario Universitario De Santiago
    • Madrid
      • Madrid, Madrid, Spain, 28040
        • Recruiting
        • Hospital Clínico San Carlos
        • Contact:
        • Principal Investigator:
          • Noelia Sanmamed Salgado, MD
        • Sub-Investigator:
          • Manuel Gonzalo Vázquez Masedo, MD
        • Sub-Investigator:
          • Miren Gaztañaga Boronat, MD
        • Sub-Investigator:
          • Maria Nieves Cabrera Martin, MD
        • Sub-Investigator:
          • Natalia Vidal Cassinello, MD
        • Sub-Investigator:
          • Anxela Doval Gonzalez, MD
        • Sub-Investigator:
          • Javier Puente Vazquez, MD
        • Sub-Investigator:
          • Ignacio Moreno, MD
      • Madrid, Madrid, Spain, 28034
        • Active, not recruiting
        • Hospital Ramon y Cajal
    • Navarre
      • Pamplona, Navarre, Spain, 31008
        • Recruiting
        • Hospital Universitario de Navarra (HUN)
        • Principal Investigator:
          • Marta Barrado Los Arcos, MD
        • Contact:
        • Sub-Investigator:
          • Amaya Sola Galarza, MD
        • Sub-Investigator:
          • Elena Villafranca Iturre, MD
        • Sub-Investigator:
          • Ignacio Visus Fernandez de Manzanos, MD
        • Sub-Investigator:
          • Nuria Bultó Boque, MD
        • Sub-Investigator:
          • Xabier Gurutzeaga Peleato, MD
    • Principality of Asturias
      • Oviedo, Principality of Asturias, Spain, 33011
        • Active, not recruiting
        • Hospital Universitario Central de Asturias
    • Valencia
      • Valencia, Valencia, Spain, 46026
        • Active, not recruiting
        • Hospital Universitario y Politécnico de La Fe
    • Vizcaya
      • Barakaldo, Vizcaya, Spain, 48903
        • Active, not recruiting
        • Hospital de Cruces

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with histologically prostate adenocarcinoma, confirmed with a biopsy.
  • Testosterone in biochemical castration ranges (testosterone <50 ng/ml or 1.7 nmol/L) and documented progression: biochemical according to Phoenix criteria or distant by radiological confirmation (PSMA PET/CT or Choline PET/CT)
  • Biochemistry progression confirmed according to Phoenix criteria, with testosterone in castration levels (testosterone <50 ng/ml or 1.7 nmol/L).
  • Radiological confirmation (with choline-PET/CT or 68Ga-PSMA-PET/CT) of ≤5 node or bone metastasis, non-visceral, eligible to receive SBRT treatment (< 3 cm major diameter in bone metastases, < 5 cm in lymph node metastases). In the case of very close metastases, a limit of up to 5 treatment fields with SBRT is allowed, instead of 5 metastases.
  • Patients candidate to receive treatment with abiraterone or enzalutamide as per clinical routine, and treatment selection and prescription assigned by responsible physician before the inclusion in the study. or or who has started treatment no more than 14 days prior to signing, as first-line treatment after a diagnosis of oligoresistance.
  • Patients must provide written informed consent.
  • Life expectancy > 3 months.

Exclusion Criteria:

  • Patients with prostate carcinoma with histology other than adenocarcinoma.
  • No previous biopsy.
  • > 5 metastasis, not approachables in 5 treatment fields
  • Patients with visceral metastasis and or metastasis non elegible to receive SBRT.
  • Patients with Testosterone above castration levels
  • Patients with prior treatment with docetaxel as first-line CRPC treatment (previous docetaxel treatment is permitted when administered as hormone-sensitive metastatic prostate cancer treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Second generation antiandrogen plus SBRT
Each patient will be included in the study once the second generation antiandrogen is initiated (which will be maintained until radiological progression, suspension due to poor tolerance and/or exitus). SBRT will be performed at least 2 weeks after initiating treatment with second generation antiandrogen, without exceeding 8 weeks from the start of treatment, and follow-up will continue up to a maximum of 36 months after completion of SBRT and/or exitus
Drug: Xtandi
Each patient will be included in the study once the second generation antiandrogen is initiated (which will be maintained until radiological progression, suspension due to poor tolerance and/or exitus)
Drug: Zytiga® (Abiraterone Acetate)
Each patient will be included in the study once the second generation antiandrogen is initiated (which will be maintained until radiological progression, suspension due to poor tolerance and/or exitus)
Other Names:
  • abiraterone acetate
Radiation: SBRT
SBRT will be performed at least 2 weeks after initiating treatment with second generation antiandrogen, without exceeding 8 weeks from the start of treatment, and follow-up will continue up to a maximum of 36 months after completion of SBRT and/or exitus

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Determine the PRFS
Time Frame: From the start of the study (the day it begins) or up to 14 days before the start of the study (corresponding to the start of treatment with second-generation antiandrogens) until the time of radiological progression during follow-up, it can be up to 36.
Determine the PRFS measured from the time of initiation of second-generation antiandrogen to the time of radiological progression by choline PET/CT or 68Ga-PSMA PET/CT, in patients with mCRPC treated with the combination of second-generation antiandrogen
From the start of the study (the day it begins) or up to 14 days before the start of the study (corresponding to the start of treatment with second-generation antiandrogens) until the time of radiological progression during follow-up, it can be up to 36.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Overall survival
Time Frame: From the start of second-generation antiandrogen therapy (at baseline or up to 14 days prior) to the date of death from any cause, assessed up to 36 months.
Overall survival (time from initiation of second-generation antiandrogen to exitus) in patients with mCRPC treated with the combination of second-generation antiandrogen plus SBRT.
From the start of second-generation antiandrogen therapy (at baseline or up to 14 days prior) to the date of death from any cause, assessed up to 36 months.
Quality of life by EORTC scale
Time Frame: from recruitment to the end of patient follow-up (up to 36 months)

QoL using the European Organization for Research and Treatment of Cancer (EORTC) quality of life scale, EORTC QLQ-C30, validated for oncology patients.

The scale converts all scores to a standardized range from 0 (minimum) to 100 (maximum). A high score indicates a better outcome (high quality of life and good health).
from recruitment to the end of patient follow-up (up to 36 months)
Acute and chronic toxicity
Time Frame: from recruitment to the end of patient follow-up (up to 36 months)
Acute and chronic toxicity according to the "Common Terminology Criteria for Adverse Events" (CTCAEv5.0) scale
from recruitment to the end of patient follow-up (up to 36 months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Instituto de Investigación en Oncología Radioterápica - Fundación Española de Oncología Radioterápic

Collaborators

Fundacion Miguel Servet

Investigators

  • Principal Investigator: Marta Barrado Los Arcos, MD, Hospital of Navarra

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 16, 2024

Primary Completion (Estimated)

May 16, 2030

Study Completion (Estimated)

May 16, 2030

Study Registration Dates

First Submitted

July 13, 2026

First Submitted That Met QC Criteria

July 16, 2026

First Posted (Actual)

July 21, 2026

Study Record Updates

Last Update Posted (Actual)

July 21, 2026

Last Update Submitted That Met QC Criteria

July 16, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRA-RAD-2022-001
  • 2023-505024-62 (EudraCT Number)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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